PHILADELPHIA – Ivy League professor Rafael Robb was an expert in game theory, a complex melding of psychology, human behavior and economics — all aimed at determining what one's adversary will do next.
With that background, police say, Robb may have thought he could outsmart them.
Robb was arrested and charged this week with bludgeoning his wife to death after what police said was a bungled attempt to make it look like a burglary.
"The efforts to throw police off were amateurish," District Attorney Bruce Castor said.
Police said the 56-year-old tenured professor at the University of Pennsylvania killed his wife in the kitchen of their suburban home Dec. 22 because he feared a ruinous divorce.
As they analyzed the crime scene, investigators realized that glass from a broken window had not been trampled on. The family dog, which had been locked in a bedroom, did not bark. And Robb's alibi — that he was in Philadelphia — did not entirely check out.
And, police added, no stranger would have beaten the stay-at-home mother and Girl Scout leader beyond recognition.
"This was an attack that was designed to punish somebody who was threatening him," the district attorney said.
Police believe Robb feared a divorce would wreck him financially and his seemingly close relationship with his 12-year-old daughter. The divorce lawyer had told Ellen Robb she could expect about $4,000 a month for 10 to 15 years.
If convicted of murder, he could get life in prison.
Friends knew the couple kept separate bedrooms, and could see the tension between husband and wife.
"I, unfortunately, in the last couple years, did not have any conversations with her because she was withdrawn so much," said Becky Best, who was maid of honor at the couple's 1990 wedding. The couple had met through a dating service a few years before their marriage, she said.
"I think she was probably embarrassed with the situation," Best said Tuesday.
The Robbs had lived separate lives for years, but remained under one roof as they raised their only child.
That fragile equilibrium started to break last year, when Ellen Robb hired a divorce lawyer, leased an apartment, and confided to a friend that Robb had struck her, authorities said. She planned to move out Jan. 1.
"Lots of people stay together for the sake of a child, but it was coming to an end," Castor said. "I think Mrs. Robb had gotten to the point that she couldn't take it anymore."
Four days before her 50th birthday, Ellen Robb was beaten as she wrapped presents in the kitchen of their Upper Merion home. Robb told police he discovered her body after dropping off his semester grades at Penn.
Police questioned Robb's supposed response to finding the body. Robb said he touched his wife's body and brought his briefcase and laptop computer upstairs. He then checked on the family dog, stopped in the bathroom and laundry room, and walked to his car before calling for help from a cell phone, according to court papers.
Susan Gay, who got to know Ellen Robb through their daughters, described Robb as "aloof." He was "a man of few words. Very distant," she said.
Defense lawyer Francis Genovese said police still have no physical evidence to tie Robb to the crime, even after searching his home, office and car, and taking blood and fingerprint samples.
"People get divorced all the time," Genovese said. "I don't know that he was upset or concerned enough that he would murder his wife."
Game theory is used in economics to analyze consumer behavior, in business to understand complex deals, and was also widely used throughout the Cold War to develop nuclear strategies.
Penn officials declined to comment, noting only that someone else would be taking over Robb's coursework this semester.