"It occurred in a moment of madness, none of it planned nor stoppable," Robb said. "More than anyone, I scarred our daughter Olivia for life. I can't imagine what goes through her mind when she is asked about her parents."
Robb, once a tenured economics professor at the University of Pennsylvania, pleaded guilty to voluntary manslaughter a year ago.
He admitted he "just lost it" during an argument that erupted at the couple's Upper Merion Township home in December 2006. Ellen Robb had been planning to end their 16-year marriage, and her husband feared he would see less of their daughter and possibly suffer financially if they divorced.
The couple began fighting over the schedule of a mother-daughter trip to Boston that had been planned for the school break. After the attack - in which Ellen Robb was so badly bludgeoned that investigators initially thought she had been shot in the face - Robb staged a burglary and ditched the murder weapon in Philadelphia.
The defense argued that Ellen Robb had long suffered from severe obsessive-compulsive disease and depression, rendering her incapable of caring for herself, their child or the house. She hoarded purchases, stacking them from floor to ceiling in nearly every room of the house, they said. The tension and dysfunction led Robb to snap, lawyer Frank DeSimone said.
"The crime scene detectives couldn't even get through the house," DeSimone said. "How does a child live there?
Ellen Robb tried 27 different medications over the years, along with some counseling, but the judge questioned if more shouldn't have been done to help her. Perhaps a therapist or family member should have had her hospitalized, he said.
"There were a lot of people who failed this woman," Montgomery County Judge Paul W. Tressler said.
Arthur Gregory, the victim's brother, said his sister started hoarding things because Robb - who ultimately earned about $200,000 a year at Penn, where he specialized in game theory - would not regularly give her household money. She then went overboard when he would surrender a credit card or when she withdrew money from a family trust, Gregory said.
"They tried to paint my sister as the one with all the problems," Gregory said afterward.
Tressler said he had been weighing a lighter sentence but decided against it after learning of a letter the former professor sent his daughter this week from prison.
In it, Robb wrote that he would not send Olivia a Christmas present until she sent him her report card and a school photo, the judge said. Tressler said he did not want Robb manipulating his daughter.
Gregory delivered the items Wednesday, and Robb studied them during the hearing.
The daughter, now 14 and a high school freshman, is being raised by Gregory in Haddonfield, N.J. He asked Tressler to keep Robb in prison until Olivia finishes high school and can decide for herself whether to resume contact - something Robb said he desires.
Robb - who is being treated for stomach and thyroid cancer - is eligible for release in January 2012, given the time he has already spent behind bars. His daughter is due to graduate high school that June.