Did This Game Theory Expert Plot the Perfect Murder?

Ten years after he bludgeoned his wife to death in their Upper Merion home, world-renowned game theorist and former Penn prof Rafael Robb is a free man. And the killing of Ellen Gregory Robb has come to look less like the crime of passion he was convicted of and more like the act of a methodical, calculating mind.

A police car at the Robb home in January 2007. Photograph by Matt Rourke/AP

Gary Gregory drove toward his sister’s house that afternoon with a short workday in the rearview mirror and a happy week ahead. His sister, Ellen Gregory Robb, had spent years trapped in a loveless marriage, trying to save the relationship until the fall of 2006, when, during one of their furtive phone calls, she confessed, “I don’t want to do this anymore.”

Gary seized the moment. “Maybe you should go.”

Ellen raised practical concerns: Her husband, Rafael Robb, a University of Pennsylvania economist, earned all the family’s money; their daughter, Olivia, was only 12.

“How will I pay for a divorce attorney without Rafi knowing?” she asked. “He controls all the money! How will I ever support me and Olivia?”

“Don’t worry about money,” Gary told her. “I’ll pay for the attorney. I’ll get you and Olivia started in a new place.”

Gary had once liked “Rafi” but came to consider him toxic to his sister’s well-being. On December 22, 2006, having made good on his promise to get her an attorney, he drove to Ellen’s house in Wayne to complete the rescue mission.

He turned the radio on, determined to whisk Ellen and Olivia out of trouble and into joy: Christmas at his home in Boston, and a 50th birthday celebration for Ellen the following day.

He turned onto Forest Road, a wide, tree-canopied lane in Upper Merion, feeling a rare lightness in his heart. Then, a puzzle of unexpected images: police cars, an ambulance, crime-scene tape.

He parked.

“Who are you?” asked a patrolman.

“I’m the brother of the woman who lives in that house,” Gary said.

“Your sister is dead,” he was told.

Someone chauffeured him to the station, where a detective asked, “Does your brother-in-law own a gun?”

Ellen Gregory Robb’s death, among the most violent in the region’s history, would garner national headlines, yielding a tragic, teachable moment in the annals of domestic abuse cases and a seemingly sophisticated, diabolical killer. Rafael Robb was an Ivy League professor and expert in economic game theory — a method of scrutinizing not just business deals, but every human interaction, to obtain the most favorable outcome.

Robb ultimately achieved his favorable outcome. He avoided trial on first-degree murder charges by negotiating a manslaughter plea that cast his wife as provocateur. Rather than risk rotting in jail, Robb served just 10 years. Now he lives in a Pittsburgh suburb — in a cluttered second-floor apartment in a cheerless building — and under a cloud of questions: To what extent did his brilliant mind factor into the crime and his favorable plea deal? Was manslaughter the appropriate charge, or did he plot to kill his wife? Meanwhile, Gary still fights for his sister — to establish what really happened to her, and to expose what he believes to be the true nature of his brother-in-law, the economist who gamed the legal system and won.

Left: Ellen Gregory and Rafael Robb on their wedding day in 1990 (courtesy of the Gregory family). Right: Gary Gregory at Every Great Reason Foundation headquarters in Holliston, Massachusetts (photograph by Josh Andrus)

Rafael and Ellen started life thousands of miles apart, in geography and temperament.

Born in 1950, Robb grew up in Israel. His parents, Holocaust survivors, never spoke of the horrors they’d faced but — he later stated in court proceedings — taught him to “abhor violence.”

Robb’s father ran a tailoring shop, worked late nights, and urged his son to get a good education. Robb got a bachelor’s degree in economics and math at Hebrew University, the Harvard of Israel, then emigrated to the U.S., where he received a master’s degree and a PhD in economics at UCLA. In 1984, he joined the faculty at Penn. He met Ellen through a dating service.

“He had some strange ways about him,” says Gary, “but they were easy to dismiss as cultural differences or eccentricities.”

In old photos, Robb cuts a somewhat blank figure. He’s tall and broad-shouldered, but his face is big and mostly empty, his features minimalist. Controlling, particularly about money, he insisted — before and after marriage — on maintaining separate finances. At Gregory family parties he was quiet and sometimes rude, sweeping tangerine peels and nutshells off the table and onto the floor.

“Rafi!” someone would say.

“Ehhh?” he’d respond, like he didn’t quite understand. He left the garbage for someone else to clean up.

He declined to discuss his work, with stiff insults. “It’s deep,” he’d say, in heavily accented English, or, “I could try to tell you, but you wouldn’t understand.”

Robb and Gary, the youngest of three Gregory siblings, often huddled, discussing business. “I think he recognized that I was in the real world dealing with the problems that he was theorizing about,” says Gary.

His brother Art, however, joined aunts and uncles in urging Ellen to end the relationship. “I said to her many times,” remembers Art, who lives in Montdale, “‘Do you really want to be with this person?’”

“I love him,” Ellen protested, leaving her family little choice.

They wanted happiness for her particularly because of the tragedy they faced as children. Their father, a financial officer for an American company in Colombia, took his wife and three kids to live abroad. But he suffered an untimely death, going into diabetic shock when Ellen, the eldest child, was seven. The family reconnected with aunts and uncles and moved to Rosemont, where Ellen earned the nickname “Little Mother.”

“Whatever I might have needed,” recalls Gary, “I just remember that Ellen was always there to provide it for me.”

Food. Hugs. Band-aids. Ellen was there. She worked her way through school at the College of Textiles & Science (now Philadelphia University) by nannying, among other jobs, and sent home her benefit checks from their father’s death. In 1979, she got a job in the management training program at Bamberger’s; she then worked in sales for Hanes Hosiery. In her early 30s, she was a petite and happy-looking woman, her hair swept back to reveal a confident face.

She wasn’t sure about Robb at first. She was an extreme extrovert, popular in school for knowing the location of the next, best party. He was so quiet. But he boasted a plum job at Penn and took her to fancy restaurants in Center City, and his work offered the promise of visiting professorships abroad, recalling her father, the international businessman. She had also always been honest about her chief ambition — to be a mother.

Rafael, Olivia and Ellen Robb in an undated portrait. Photograph courtesy of the Gregory family

The day after Ellen Gregory Robb was killed, Montgomery County District Attorney Bruce Castor visited the crime scene.

Investigators had already zeroed in on Rafael Robb, who’d phoned the local police precinct rather than 911. “I just came home and found my wife murdered on the kitchen floor,” he said. “Her head is cracked.”

He talked to police freely, initially saying he last saw Ellen around 8:30 a.m. She was wrapping gifts in the kitchen. Olivia was at school. He departed, stopping in Chinatown for fruit and at the Wawa near Penn for soda. Then he dropped off grades at the university and left for home around noon, discovering his wife on the kitchen floor.

He briefly touched her face, could see that she was dead, and went upstairs. He left his laptop and briefcase on his bed, then heard the family shih tzu, Copper — who normally had the run of the house — barking in his daughter’s bedroom. He checked, concerned that Olivia might have come home early, but found only the dog. Then he walked back downstairs, to call the police, but suddenly had to urinate. He went to the bathroom down the hall and saw glass from the rear door shattered. Finally, he called the local precinct.

Investigators quickly discovered inconsistencies. Robb acknowledged the marriage as loveless — the couple slept in separate bedrooms. But he denied that divorce was imminent, a detail Gary Gregory contradicted. Further, who finds his wife dead on the floor and considers peeing before calling the cops? Who doesn’t call 911?

Some of his alibi checked out: He drank an entire soda in front of a Wawa surveillance camera; Penn confirmed he’d dropped off grades. But employees at a Chinatown produce store he frequented didn’t recall him visiting that day, and the supposed break-in at his house looked fake.

Castor stood in the hallway, examining the broken rear door. The glass lay in perfect shards. A burglar would have crushed it underfoot. He walked back into the kitchen. Blood still stained where Ellen’s head had rested and was spattered across the floor, kitchen cabinets and ceiling.

Castor had already viewed the crime scene photos, among the grisliest of his career. Ellen’s face was unrecognizable, concave, creating a bowl of blood that obscured her features. Investigators immediately deduced that the damage was consistent with a close-range shotgun blast. But forensic pathologist Ian Hood found something unexpected.

Washing the blood away, he found no buckshot. Instead, her face and forehead were crushed, revealing brain matter. Multiple lacerations cleaved her face — suggesting blows with a long, thin object. The most perplexing part of Robb’s initial call to police suddenly made sense. He’d called his wife’s head “cracked” — a peculiar way to describe a shotgun blast, but precisely the way to foretell Hood’s finding.

Hood informed Castor: The killer “used far more force than necessary,” a sign he or she knew, and hated, the victim. Castor began thinking that the facts fit a “rage killing,” a murder he defined as “resulting from a sudden passion.”

Castor had walked in the door as one of the region’s star prosecutors, having won convictions against Craig Rabinowitz, the stripper-obsessed Main Line husband who killed his wife, and chef Guy Sileo Jr., who’d killed his business partner at the General Wayne Inn. Some prosecutors keep a low profile; Castor liked the spotlight, cutting an iconic figure in pin-striped suits and cowboy boots. In Rafael Robb, he’d found another high-profile murder suspect.

He explored the house, finding it nearly impassable, clogged by furniture wrapped in plastic and great heaps of boxes, many unopened. Ellen, family and friends admitted, was a hoarder. And from the condition of both the house and the victim, Castor felt he understood the killer’s mind.

Robb, he surmised, must have snapped into a rage, killing his wife. Then, as rationality returned, the game theorist re-emerged to stage the crime scene.

Two years later, at Robb’s sentencing hearing, Castor would recall what he thought as he surveyed the blood, broken glass and boxes: He was likely not looking at premeditated murder. He was “probably” looking at manslaughter — a man with no prior criminal record who lost his mind.

The afternoon Castor visited the crime scene, however, Gary Gregory sat about three miles away, grieving. He was about to begin an investigation of his own.

The morning after Ellen’s body was discovered, police asked Gary to wear a recording device and catch Robb in some slip-up. Gary agreed, setting his feelings aside — even hugging his brother-in-law in a hotel parking lot. “If I ever had any doubts,” he says, “they were gone. When I put my arms around him, there was no feeling there, and I knew … he killed Ellen.”

Robb, however, stuck resolutely to the story he told police. The revelations Gary received came from Ellen’s friends, put together with what he’d already known.

The couple, wed in 1990, quickly encountered marital troubles. Robb even left Ellen in 1993 when she became pregnant with Olivia. She lived throughout her pregnancy with Art, who says Robb showed up late for his daughter’s birth, exclaiming: “She couldn’t even give me a son.”

They reconciled but slept in separate bedrooms. And Art says his sister gave up working, at Robb’s suggestion, to become a stay-at-home mom. Robb’s attendance at family parties dwindled. And in 1999, after a long trip to Israel for a visiting professorship, things got worse.

Gary’s wife, Kim, says she could hear Robb in the background of phone conversations: “He’d call her a ‘stupid piece of shit.’” In person, Ellen confessed to Kim that Robb demeaned her, saying that after she finished cleaning the bathroom, he’d undo his pants in front of her and urinate in the sink. By around 2004, Gary knew his sister faced serious trouble. She began speaking over the phone in code, rating her tension on a scale of one to 10 if Robb was near enough to overhear. “That obviously suggests fear,” says Gary.

The family asked Ellen if Robb was ever physically abusive, but she always said no. “She’d say it was all emotional,” says Gary, “just insults.”

At Ellen’s memorial service, Gary met with his sister’s friends to find out what they knew. Around their Wayne neighborhood, the couple had once appeared at least superficially content. Both parents doted on Olivia. And their house qualified as “a show home,” decorated with paintings collected on their frequent trips. “It was all very tasteful and immaculate,” says neighbor Mary Beth Pedlow. They had rented it out while in Israel and returned to find it in shambles. Ellen, says Pedlow, was angry enough to pursue damages, but Robb merely kept the security deposit. “He didn’t lift a finger to put the place back in order,” says Pedlow. “I think something in Ellen’s spirit kind of broke then.”

Over the years, Robb seemed to broadcast his superior position in the relationship, driving new BMWs while his wife shuttled around in a beat-up Subaru. “That always suggested something was wrong,” says neighbor Sharon Sellman.

As the years passed after that trip to Israel, Ellen confided to friends like Pedlow, who’d known her since they were both Bamberger’s trainees, that she thought about leaving her husband. But Robb, she said, threatened to take Olivia to Israel so she’d never see her again.

Another friend, LuAnn Dubin, had a kind of window into the house. Her daughter, Brooke, had been close with Olivia for years. But by around 2003, Brooke would go for sleepovers, then call before bed: “Can you come pick me up?” The house had become uncomfortable for her. Some nights she heard yelling, fights, dishes breaking. Other times she heard Robb speak disparagingly to Olivia about Ellen, often telling the girl her mother had “no money.”

There were no calls to police about domestic trouble in the Robb house. And after her mother’s death, while her father maintained his innocence, Olivia told investigators she never saw any violence. But in the years prior, suspicions had grown among Ellen’s friends. They, too, asked her: Does he ever physically hurt you?

She denied it, sometimes in ways that haunted them. “She’d say, ‘No, it’s mostly yelling and insults,’” remembers Dubin. The “mostly” caught her ear, even then.

Gary heard these stories in pieces. “I had this sense that the whole thing had been like a puzzle,” he remembers, “and it was like Ellen gave everyone different pieces, and when you put them together it was so obvious how bad it had been for her.”

The week of the funeral, one of Ellen’s old high-school friends gave Gary the most alarming piece of all. Becky Rector had invited Ellen to attend her birthday party that October. “She told me she was embarrassed,” says Rector today. “She had a black eye, and her husband gave it to her.”

The old friends talked on the phone, recalls Rector, for almost two hours. Rector pulled over in a parking lot to cry along with Ellen. Robb had always been controlling and cold, her old friend told her. He withheld money, forcing her to spend a $40,000 inheritance from an aunt on household expenses. But something had changed on that trip to Israel.

Ellen suspected that Robb’s father abused his mother. She also suspected that his father never accepted his son’s marriage to an American gentile. Somehow, she thought, being around his father set Robb further against her. Ellen shared this information with numerous relatives and friends. But that day on the phone, Ellen went further, admitting that Robb hit her.

“You and Olivia can live with me!” Rector pleaded.

“Don’t worry,” she said. “My brothers are taking care of me. I’m leaving him.”

In the weeks before her death, Ellen’s loved ones saw her grow lighter, “happier,” as she made plans, says Sellman, to “leave that house of clutter behind.” But then she was gone, and her husband was still very much alive.

In fact, he showed up at his wife’s funeral — the chief suspect milling among the mourners in a cardigan and slacks, not even wearing black. The puzzle pieces Ellen had left behind looked so obvious now, particularly in light of Robb’s behavior.

He jumped in among the pallbearers, grabbing a handle of his wife’s coffin with one hand while holding a cup of coffee in the other. During the wake, he broke down over her closed casket, tearlessly sobbing. “Oh, Ellen!” he shouted. “I can’t believe it! What will I do without you?”

Everyone stood and watched, remembers Kim Gregory, “because there was no emotion in his voice. It was like he understood what he was supposed to do, but he didn’t feel it.”

By the time of his wife’s murder, Rafael Robb had become one of the world’s foremost experts on game theory, a discipline that analyzes human decision-making through economics. In game theory, any negotiation can be modeled by assessing each party’s options and the associated risks and rewards, allowing practitioners to think many moves ahead to assure a positive outcome.

More than 10 years after Robb killed his wife, his academic standing remains high. As of March 2017, the website RePEc — Research Papers in Economics — still ranked him in the top five percent of economists in the world.

The most important insight of game theory is that we’re all playing, all the time, even if we’re unaware of it. Game theorists model corporate takeovers, legal cases, even domestic squabbles like when to wash the dishes. Fixed costs, such as the time expended to roll up your sleeves and get out the dish soap, can be weighed against practical and even emotional payoffs. A happy spouse can mean a happy life.

“Any court case, criminal or otherwise, is particularly amenable to game theory,” says Dirk Mateer, a senior lecturer in economics at the University of Arizona, “and a plea negotiation especially so. I would be very surprised if Professor Robb was not using game theory at that point.”

Bruce Castor had to determine where the game theorist in Robb began and ended. If all Robb’s moves, the killing included, reflected his methodical mind, Castor was looking at premeditated murder — an act that could mean the death penalty or life in prison. Castor, of course, had theorized manslaughter as more likely. But whatever his feelings, on January 8, 2007, about two weeks after the killing, he had Robb arrested and charged with first-degree and third-degree murder. The affidavit of probable cause, filed by detectives David Gershanick and Drew Marino, lists a motive and a set of facts indicating premeditation.

Ellen’s divorce attorney, Al Shemtob, told police he’d advised her she’d receive about $4,000 a month from Robb for perhaps as long as 15 years, totaling up to $600,000. Police also turned up a real estate agent who’d shown the Robbs a $1,550-per-month apartment she planned to rent.

Money, detectives determined, was Robb’s motive. The evidence against him was circumstantial but compelling.

Robb altered his timeline, trying to stretch his alibis to cover the time of his wife’s murder. He staged the burglary. He made that telltale slip, describing his wife’s head as “cracked.” And he fell for the ruse of an undercover officer who arrived with a glazing company to repair the broken glass. The cop, posing as an ex-con, advised Robb to make a list of missing items to bolster his burglary claim. Shortly thereafter, Robb told the officer he’d supplied his attorney with such a list. He also invited the undercover officer out for a drink.

The affidavit cites Rector, alleging Ellen told her of physical abuse, and lays out the crime scene. Ellen’s hands were badly damaged, two fingers crushed. The pen she’d been writing cards with was snapped, suggesting she’d fought. These defensive wounds were consistent with the idea that her attacker had fully formed the thought to kill her — a requirement for first-degree homicide — and continued to beat her as she struggled to stay alive.

There was more, including the dog locked away in Olivia’s bedroom. But the most important finding in support of premeditation came from forensic psychologists. These “experts,” the affidavit states, “believe the victim was the specific target of the killer and represented a threat to him. These experts conclude the killing was ‘overkill’ designed to punish the victim for this threat by turning the victim into an ‘it’ rather than a person. The pending divorce action would threaten Dr. Robb’s financial security and his relationship with his daughter. … [T]his would account for why Dr. Robb killed his wife and the brutal manner in which he carried out the murder.”

Robb surrendered the day charges were filed, and in the days that followed, Castor — riding a tidal wave of publicity — made a big announcement: his candidacy for higher office as a Montgomery County commissioner.

From the beginning, criminal defense attorney Frank DeSimone considered his new client special. “He was very knowledgeable,” says DeSimone. “He researched me and knew my cases.”

Robb also knew that Castor, the strutting prosecutor, had lost only one homicide case in his career, in 1994 — to DeSimone, who won an acquittal of Patty Swinehart on charges she’d plotted her estranged husband’s murder. Stung, Castor long displayed a courtroom drawing from the case in his office as a reminder.

DeSimone thought a not-guilty verdict was “possible,” but considered the dog — and another detail that wouldn’t emerge in court for years — a serious threat to Robb’s chances. And for his part, Castor agreed.

During his career, the then-46-year-old Castor had visited many murder scenes that involved pets. “They walk in, especially a family pet, right in the blood,” he says, “to check on the master to see what’s wrong. Then they track the blood all over the place.”

Here, there were no bloody paw prints, no blood on the dog or tracked upstairs to Olivia’s bedroom. The evidence suggested two possibilities: Robb killed his wife in a spontaneous attack, then cleaned himself and stored the dog before it could investigate the commotion, or he plotted to kill his wife, securing the dog beforehand.

Robb maintained his innocence, and that March, Castor let DeSimone know he’d consider a plea of voluntary manslaughter. DeSimone advised Robb to think it over.

Author Rose Ciotta, who covered the case for her book Cruel Games, says Castor had legitimate concerns. He was worried primarily about the lack of direct physical evidence. There were boot prints in the blood, but it was inconclusive as to whether they matched Robb’s size 12 shoe — and no boots were recovered from the crime scene. And for all the blood, there was none on Robb, or in the sink or shower traps. “We’d begun living in a CSI culture,” she says. “Juries expect direct physical evidence and hard science because that is what they see on TV.”

Robb delayed for months before DeSimone pressed for a decision. “I advised my client, a final time, about the state of the evidence against him,” says DeSimone. “He gave me permission to seek a plea.”

Once he’d locked down the details with Castor, “I went back to my client as quickly as I could,” says DeSimone. “I told him, ‘This deal is better than anything we could reasonably have expected.’”

Robb, then 57, undoubtedly looked at the costs, fixed and potential, of a murder trial: A first-degree murder conviction merited life in prison. The manslaughter deal might get him out in as little as four and a half years. Any game theorist could weigh these choices and reach the logical conclusion, taking the deal, and something else, too: the chance to write history. Because the legal narrative of what happened to Ellen was constructed over the following year almost entirely by her killer.

Robb’s guilty plea, given November 26, 2007, remains the guiding document in his case — the set of facts he and prosecutor Bruce Castor codified. He and his wife argued that morning in the kitchen, Robb stated, over the Boston trip she and Olivia were taking. He expressed concern they’d overstay, causing Olivia to miss school. They argued, and Ellen pushed him. She was five-foot-four and overweight; he was six feet tall and fit. He fell, striking his head on the counter.

“I just lost it,” he told the judge.

A chin-up bar he’d yet to install was lying nearby. He grabbed it and started swinging. “We had mixed feelings about the plea,” Gary Gregory says today. “We thought he’d premeditated this. But we were relieved to not have a trial and to have him admit that he killed her. We were also, I think, still in that phase of thinking, ‘This is the great Bruce Castor.’”

They were painfully aware, however, that the plea positioned their sister as complicit, since it described the murder as the result of “serious provocation.” The agreement also glossed over some key evidence. Though police never recovered a murder weapon, Art Gregory had remembered a crowbar hanging in the family’s garage amid a row of tools. Detectives found the other tools, but an empty hook where the crowbar presumably hung.

This dynamic, in which Robb dictated the official history, continued. At his sentencing in November 2008, Robb, with DeSimone, created what Ellen’s loved ones remember as a “second murder scene” — this time assassinating her character.

An expert witness, psychologist William Russell, had never personally examined Ellen but testified that he’d reviewed her medical records and interviewed her husband. Ellen had become dysfunctional after Olivia’s birth, Russell testified, feeding her daughter from a bottle till she was six. Ellen was depressed, suffering from obsessive-compulsive disorder and hoarding, freely spending her husband’s money on items she piled in ever-growing stacks while the long-suffering economist made dinner and shopped for groceries.

There are “victims all over the place,” said DeSimone, who declared, flatly, “This is not a domestic abuse case.”

Gary and Art both testified but say they weren’t prepped by Castor. He’d won his race for a county commissioner’s seat and returned to the Robb case as a special prosecutor. “I think he was distracted,” says Gary. “He had his big new job.” (Castor denies being distracted, pointing out that he stayed with the case after stepping aside as DA.)

On the stand, the Gregorys were unsure of what they could say. They angered the judge with missteps, like arguing that their sister’s killing was premeditated. They could also only answer the questions asked by Castor, who didn’t push back against the image of Ellen as mentally ill.

Friends Dubin, Pedlow and Sellman sat dumbfounded. “We had gone to Bruce more than once,” says Pedlow. “‘Please, use us, we know what happened,’ and he said, ‘I’m the DA. I know what I’m doing. I’ll use you if I need you.’” What made the experience so devastating, they say, is that they had answers for just about everything Russell mentioned.

Ellen didn’t “feed” Olivia from a bottle till she was six, says Dubin: “I met them at the park. I saw them at their home. She had peanut butter sandwiches and bags of apples. He made it look like she was underfed and unhealthy. She ate solid food, and as a kid, she was a little chubby!”

The Gregory brothers, Pedlow and Dubin all say Olivia received a daily bottle of fruit juice to sweeten what Art calls a “vile-tasting” medicine she took for a digestive condition. Ellen was also one of the most involved moms in the community — baking cookies, leading a Brownie troop, and winning Volunteer of the Year at Roberts Elementary in 2004.

Dubin and Pedlow still saw Ellen at the grocery store, even in the darkest times, filling her cart at night to avoid being home with Robb. Art and Gary add that Castor looked so hard at the forest of Ellen’s hoarding that he missed the trees. “It looked worse than ever when she was killed,” says Art. “Why? Because she had been buying pots, pans, sheets, all the things you need to start a new house.”

Castor did make the obvious point that mental illness can never be an excuse for murder. But he didn’t make the case that Ellen’s depression seemed to lift right after she decided to divorce Robb. “She told me she was leaving Rafi,” says Dubin, “with this light in her eyes. She wanted Olivia to see there was a better way of living. … I was like, ‘Ellen is back!’”

Castor fought for a tough sentence: 20 years. But Judge Paul Tressler, considering, among other factors, Robb’s diagnosis of thyroid cancer, leaned toward a sentence on the low end of the five-to-10-year range for manslaughter. Then Art Gregory produced a letter while on the stand.

Robb had been calling Olivia from prison, coaxing her to send him a report card and photo of herself:

Hi honey: Just to make it easier for you I am enclosing a self-stamped/self-addressed envelope. All you have to do is print out pictures of you, make a copy of your report card, enclose them in the envelope, and drop it in a mailbox. In return you will have your holiday gift coming to you in no time.

I’d hate to delay sending you the gift, but I won’t do so unless I get these items. Remember also that I will be shipped out of the area soon. So if you don’t send the items within a day or two, I won’t get them for months, if at all. Won’t the love of money propel you into action?

Love & kisses,

The economist likely sought to show a warm relationship. Olivia didn’t comply.

Judge Tressler rejected Castor’s plea for a longer sentence but, citing Robb’s manipulative streak, did give him five to 10 years.

“I read the sentencing transcript,” says Barbara Ashcroft, a former assistant DA in Montgomery County and current director of Temple’s trial advocacy master’s program. “And I was disappointed. Because as prosecutors, the saying is, ‘We speak for the victim.’ But not this time.”

Perhaps most egregiously, Castor failed to make a case that Robb might have caused Ellen’s mental health issues. Numerous studies link various mental health conditions — including depression, OCD and hoarding — with mental and physical abuse. “The [study’s] evidence suggests that there are two things happening,” King’s College Institute of Psychiatry professor Louise Howard declared in 2012, after releasing such a study. “Domestic violence can often lead to victims developing mental health problems, and people with mental health problems are more likely to experience domestic violence.”

Gary Gregory discovered this link when he reached out to Beth Sturman, director of Laurel House, and Maria Macaluso, director of the Women’s Center of Montgomery County, to learn more about his sister. Both heard him describe Ellen’s relationship with Robb and recognized it as one they’d seen hundreds of times.

Early generosity gives way to controlling behavior. Money is often the means abusers use to control their targets. Rudeness toward the abused’s family is a way of signaling dominance. And over time, the troubles deepen. “The abuse is usually emotional at first,” says Sturman. “But then it escalates into something physical.”

Half of abused women don’t go to the hospital or call the police. And Ellen’s habit of giving small clues to various people is typical. Macaluso calls this a muted cry for help from someone who “is probably still blaming themself.”

Finally, the abused partner is never in more danger than once he or she has decided to go. “There is a window,” says Macaluso, “from right after the partner says ‘I’m leaving’ till about a year after they’ve gone when they face the greatest danger.”

Anyone aware of the patterns, both women say, would recognize that the murder of Ellen Gregory Robb was always a classic case of domestic violence. They also say it’s common for people to underestimate claims of emotional abuse. But there’s something more. Macaluso grew interested enough in game theory, because of this case, to start reading. She recognized not just the Robb case, she says, but every case she’s handled: “Every abuser is using it, narrowing their partner’s choices, making it easier for them to choose giving up control than anything else.”

There are, then, two possible views of Robb: the one he presented in court, in which a world-renowned academic, beset by his wife’s long-standing mental illness and a sudden provocation, “lost it”; and another, advanced by those who knew Ellen and understand domestic violence, in which he emerges as something else altogether: an entirely average criminal.

The weekend his sister died, Gary Gregory turned to his wife, Kim, in their hotel. “We have to find some way to turn this tragedy into triumph,” he said.

“That’s Gary,” says Kim now. “He is very good at compartmentalizing and slipping back and forth between being a brother and being a pragmatic, rational CEO.”

In the tale of Ellen and Rafael Robb, Gary serves as his brother-in-law’s chief foil. Steeped in economics himself — he long served as the COO of Neurometrix, a Boston-based company that sold medical devices — he set out to keep his sister “alive in some way.”

Early in 2007, he founded Every Great Reason, the initials matching his sister’s, to raise domestic abuse awareness. The nonprofit distributes the information he wishes he’d had when his sister was still alive.

Over the years, as Ellen tried to work things out with Robb, Gary “encouraged” her efforts, not understanding the seriousness of emotional abuse. He’d also driven into Wayne from Boston the night before his sister’s murder, thinking he’d get more work done if he stayed at a nearby hotel. He didn’t know those hours were so crucial.

Gary Gregory fights back tears, his long, jowly face shaking. “That’s the big bag of rocks I carry to this day,” he says. “The ways in which I failed Ellen.”

In the years since, however, Gary started stacking up victories.

Robb sought parole, as his sentence allowed, after five years, and on November 7, 2012, the state parole board acceded, noting his good behavior and acceptance of responsibility. But Gary rallied a public firestorm in which both Castor and Tressler joined.

The judge wrote a letter detailing Robb’s “manipulative” behavior toward his daughter, which Art and Gary say continued from prison. The parole board rescinded its decision. Afterward, Gary partnered with State Representative Mike Vereb to pass a bill they call “Ellen’s Law” that lets survivors address the parole board before members vote. So far, more than 5,000 survivors have appeared. “Each one,” says Gary, “represents some victory for Ellen.”

The fight to keep Rafael Robb in prison became an annual ritual, as he continued to apply for parole and the family continued to oppose it, eventually using the law Ellen had inspired to address the parole board. Each time, they won, ensuring that Robb served every last day of his 10-year term.

They also got to see Robb on the witness stand. The family’s civil attorneys determined Robb had assets of around $3 million, mostly from pension and investment funds. “We want that money for Olivia,” Gary says of his now-23-year-old niece.

The family filed a wrongful death suit against Robb, hiring renowned civil attorney Bob Mongeluzzi for what became an explosive 2014 trial. Olivia testified, amending what she’d told police to indicate that she had been afraid of her father — that he had a violent temper. But Rafael Robb was the key witness, finally forced to answer questions beyond what he had admitted in his plea.

Robb had barely settled into the witness chair when Mongeluzzi advanced. “You are a killer and a liar, Mr. Robb, aren’t you?”

“Killer, yes,” Robb responded. “Liar, too, yes.”

Mongeluzzi also revealed stunning evidence never previously introduced in court. Detectives had recovered a full-body protective suit and facial masks from Robb’s car. The suit was still wrapped, but its importance seemed obvious to Robb’s attorney, DeSimone — who thought it “a serious concern” — and to Mongeluzzi, who elicited civil testimony from a detective describing the find as a hazmat suit.

What, he asked, would the economics professor be doing with a suit like that?

Gary had never heard about the suit — not from detectives nor from Castor — until Mongeluzzi told him about it prior to trial. “I don’t remember where we were,” he says. “I was so devastated, I think I just blocked all those memories out.”

At the civil trial, Mongeluzzi argued that Robb likely owned more than one such suit, which would explain how the econ professor managed to escape such a bloody crime scene without leaving traces on himself, in the house’s plumbing or in his car. But he never questioned Robb about the suit, instead asking him to describe what he did after he killed his wife.

Robb testified that he dropped the murder weapon, wandered out to the garage, and realized he was covered in blood. He returned to the kitchen, he said, near his dead wife, and stripped off his bloody clothes. He removed his shirt, then his boots, balancing on one leg and standing on them to avoid leaving any footprints. Then he removed his socks and pants the same way till he stood atop a pile of bloody clothing. The scene conjures black comedy: Robb walking on tiptoe, to avoid leaving any marks in the blood all over the floor.

Upstairs, he went into the bathroom. There, he kept a box of large lawn and leaf bags and baby wipes. He used the wipes to clean himself and placed them all inside a leaf bag. Then he dressed himself and took the bag to the murder scene, somehow leaving the evidence uncontaminated as he sacked up his clothes and the undoubtedly gory murder weapon.

Mongeluzzi attacked the improbable account. How could he have gone upstairs without any blood from his skin dripping on the floor? How could he have stepped back into that “slaughterhouse” in new shoes and removed the murder weapon and his bloody clothes without leaving a trace?

Most damningly, if he actually did walk into the garage, still in his bloody boots, and then return to the kitchen, why did the boot marks only point in one direction — out to the garage? Wouldn’t it make more sense, Mongeluzzi argued in his closing, to think Robb planned the whole thing, donning a second suit, murdering his wife, and then walking out to the garage? Didn’t it make more sense to believe the blood trail stopped there because that’s where Robb bagged everything, emerging — just as the suit was designed — clean?

The civil trial didn’t hinge on proving that Robb committed first-degree murder. But the verdict was punitive: a massive $124 million judgment. Gary Gregory describes the victory as “Pyrrhic.” Robb performed poorly on the stand, but Gary was more convinced than ever that pleading guilty to manslaughter had allowed his brother-in-law to get away with murder.

Today, about 289 miles apart, Rafael Robb and Bruce Castor live very different lives. In the years since Ellen’s death, Castor has undergone a series of professional changes. He quit as county commissioner after eight years, in January 2016, then served briefly as acting state attorney general after Kathleen Kane was convicted of perjury. He also ran to win back his seat as Montgomery County DA, but lost a punishing race in which two old decisions were used against him: his handling of the Robb case, and his decision not to prosecute Bill Cosby in 2005, when Andrea Constand accused him of sexually assaulting her.

Castor calls Cosby — now accused of sexual assault by 60 women — the “victim of the biggest lynching I’ve ever seen.” And in the tidy office he now occupies in Ardmore, he defends his actions in the Robb case, too.

Earlier this year, on a TV show called Crime Watch Daily that aired shortly after Robb’s release, Castor appeared to contradict his decision to accept a plea. “He intentionally locked the dog away,” he said of Robb, “before he went to do the killing.” If that was indeed the order of events, Robb certainly committed first-degree murder. Asked about the line, Castor expresses surprise that he said it. “I don’t remember,” he says. “I don’t remember what the question was.” He adds that any notion the dog was closed away first “would go against the theory that it was a rage killing.”

Castor cites Timothy Michals, a forensic psychiatrist mentioned in the initial affidavit supporting Robb’s arrest, as endorsing the theory of a rage killing. But Michals’s opinion was initially used in the affidavit to support a first-degree murder charge. Reached recently, he said the finding of a “rage killing” speaks to the relationship between the killer and the victim — not to impulsivity or premeditation. “It’s possible,” says Michals, that a first-degree homicide could involve a rage killing.

A forensic psychologist, Michael Bourke of the U.S. Marshals Service, agrees. “The fact that this killer was guilty of overkill, of trying to obliterate the victim’s identity, would tell me this murder was personal,” he says. “It wouldn’t tell me if it was first-degree murder or a crime of passion. It could be either.”

Castor insists he is undaunted. Does he think the case might have been first-degree murder? “No,” he says flatly. “Is it possible someone could engage in a rage killing and have premeditated it? I suppose. But I’ve never seen that.”

This statement is itself surprising, even inexplicable. “First-degree murder cases occur in ‘rage killings’ all of the time,” says former Montgomery County ADA Barbara Ashcroft. In one of the most notorious trials of the TV news age, Jodi Arias was convicted of murdering her ex-boyfriend, Travis Alexander, in a dramatic case of overkill. Arias stabbed her victim 27 times, slit his throat, and shot him in the head. Closer to home, Ashcroft successfully prosecuted Charles Granese for first-degree murder in what she calls “an obvious case of overkill.” Granese stabbed his wife, Christine, at least 10 times, including two wounds that would have been fatal. Ashcroft’s boss at the time, the Montgomery County DA, was Bruce Castor.

To Ashcroft, the case against Robb was circumstantial but “strong.” The dog and the unopened protective suit, she says, were particularly powerful. “A man as methodical as that might be expected to have a second suit,” she observes, “one to do the killing and another in case he needed to go back in and manipulate the scene.”

She echoes Ellen’s supporters on another point: Castor’s stance on Ellen’s hoarding seems not just ineffectual, but offensive. In an interview, Castor repeatedly raises the subject: “I don’t know if anyone has ever told you this, but the house was awful. It is impossible for me to describe it.” Later, “It was uninhabitable,” he says. “So that led me to think there’s no chance that the husband of this woman can think this is okay.” And, “In my own mind, I thought that I would not be able to live with a wife that was like that.”

“The hoarding,” says Ashcroft, “is completely beside the point. … And if it was factored in at all, I think it should have been as something the defendant contributed to or caused.”

The defendant, however, is free and living on the other side of the state. And this past April, he was surprised to see a reporter turn up at his door.

“Come in, come in,” said Rafael Robb, dressed for warm weather in tan shorts and a blue short-sleeved shirt.

More than 10 years after his cancer diagnosis, he looked vital and fit.

His apartment, though, was another matter. The small kitchen, just off the living room, looked in need of a good scrub-down. Unwashed dishes were stacked on the counter. The dining table, too, stood covered in papers, leaving just a small space cleared for him to eat. He had to move boxes and magazines from the couch to create a place for me to sit; when he wanted a soda, he pulled it from a big cardboard box on the living room floor.

Bruce Castor was overwhelmed by the home of Ellen Gregory and Rafael Robb. But Robb lived in those conditions for a few years — never, according to the neighbors, bringing in a crew to clear the place out. And four months after his release from jail, he seemed content to live in a new, if smaller, mess.

He spent almost 20 minutes talking before declaring he wanted the interview to be off the record, appearing by turns warm and defiant. He expressed remorse for his wife’s murder but also had business on his mind. “There are a lot of considerations,” he said, mulling the idea of submitting to a long series of interviews. “There could be a book, or a movie. … ”

Later, in an email, Robb “vehemently” denied ever hitting Ellen and rejected the claims of emotional abuse made by friends and family. He pointed out that Becky Rector never saw bruises. He also said he acquired the protective suit and mask because “I was going to do some painting work around the house.” In other instances, memory failed him: He doesn’t remember if he and Ellen kept separate bank accounts or when he put the dog in his daughter’s room.

At his apartment, he said he had no plans to restart his academic career, seeming content to live out his life in quiet retirement, if locked in a legal battle with the Gregorys. Most of Robb’s wealth is tied up in pension and investment funds that are usually shielded from civil judgment, so court battles loom.

There are aspects of the Robb case that people may point to forever as evidence the game theorist won. Whether he killed his wife with mindless fury or calculated precision, he left behind no direct physical evidence tying himself to the crime. He hired the one attorney who’d ever defeated Bruce Castor in a first-degree homicide case. And he held out his innocence till he received, all things considered, a pretty sweet deal — a sentence of 10 years or less instead of life. But a second, deeper array of data points tells a different story: Robb developed a weak alibi and a bad burglary scene, which everyone — from the patrol cops up — recognized as staged. In fact, his “success” in killing his wife and emerging, years later, as a free man appears due mostly, if not entirely, to his good fortune in facing prosecutor Bruce Castor, a man who was eyeing a higher office, perhaps haunted by one particular criminal defense attorney — and overcome by the sight of a hoarder’s house.

In this second narrative, Robb doesn’t appear all that smart. And perhaps more importantly, to those who loved Ellen, he doesn’t seem happy. In the interview at his home, he betrayed a special bitterness to the men he calls “the brothers,” Gary and Art.

“They keep showing up,” he said, “going to the media, complaining about me. Why would they still be so angry? What’s in it for them? You would think they would move on with their lives. We should all move on with our lives.”

Robb even suggested that their efforts to keep him in jail were part of a more complicated plot. They did all that, he said, to build their eventual civil case — to pose as mourners. What they really wanted, all along, was money.

His assessment reveals why he and Ellen Gregory Robb were never a good match: She seems to have been motivated in life by the emotional things people value — love and family. He, on the other hand, seems to look at the world from a place outside all that, a vantage where normal human feelings are puzzling.

Do you ever think, I asked, that maybe the brothers just hate you? Because you killed their sister?

His answer rendered him transparent, recalling the motive police originally gave for charging him with first-degree murder. “Hmm!” he said in a high-pitched exhalation, and stared off into the distance. “That could be. They want to cause me pain. But what does that actually accomplish? It is the money. That is the motivation that makes the most sense to me.”

Published in the August 2017 issue of Philadelphia magazine.