Tom Ullmann, the attorney for Steven Hayes, told the New Haven Superior Court jury in his closing argument that it was the other suspect, Joshua Komisarjevsky, who started attacking the woman's husband, Dr. William Petit, with a baseball bat.
"At every critical junction, when the plans changed it was because Joshua Komisarjevsky escalated the level of violence," Ullmann said.
Hayes is accused of killing of Jennifer Hawke-Petit and her daughters, 11-year-old Michaela and 17-year-old Hayley, at their Cheshire home. Komisarjevsky is awaiting trial.
Ullmann said Komisarjevsky was the one in control and had the motive to kill. "The sociopath or psychopath in this case is Joshua Komisarjevsky, not Steven Hayes," Ullmann said.
But prosecutors told the jury that both suspects were equally responsible.
"If he didn't like violence, why didn't he leave?" said prosecutor Gary Nicholson. "He didn't leave because he would do anything for money."
State's Attorney Michael Dearington called the crimes a "joint venture" and described how a robbery turned into a triple murder.
"What was a vibrant house became a house of terror and horror," Dearington said.
Dearington said the 47-year-old Hayes "brutally raped" Hawke-Petit, and evidence suggested that he lit the house on fire before he and Komisarjevsky fled. He also noted at several points that the crime took two people to carry out, such as when Michaela was tied to her bed while her mother was guarded in another room.
The prosecution showed photos of Hawke-Petit at a bank, where she was forced to withdraw money, and of ropes used to tie the girls to their beds. Dearington said gas was poured on or around the victims before the fire was set. Authorities said both girls died of smoke inhalation and accused Hayes of strangling Hawke-Petit.
William Petit, the girls' father and the only survivor, told the jury he awoke on a couch the morning of the attacks and found two people standing near him, one holding a gun. He said he was beaten with a baseball bat, his wrists and ankles were bound, and he was tied to a post in his basement. He managed to free his hands, get up the stairs and crawl and roll to a neighbor's house.
Jurors are expected to begin deliberations next week. Both defendants face the possibility of the death penalty if convicted.
Dearington described the day of the crime as a classic summer day in which the Petit family went to church. Dr. Petit went off to play golf with his father, and his wife and daughters had gone to the supermarket, which is where authorities say the two defendants saw the family as a potential robbery target and followed them home.
After dinner, the girls chatted and laughed together and watched "Army Wives."
But that night, a financially desperate Hayes called Komisarjevsky, Dearington said, recalling what a detective said Hayes told him. Hayes was eager to go, but Komisarjevsky told him to wait while he put his young daughter to bed, Dearington said, citing text messages the men sent to each other.
The original plan was to break into a house, tie the people up and take their money and flee, Dearington said, citing what Hayes told police. But when the men didn't find much money, the plan changed and Hayes took Hawke-Petit to the bank to withdraw money, he said.
It was at that point that Hawke-Petit would have gotten a good look at Hayes' face, Dearington said, noting he was no longer wearing a mask.
When Hayes returned with Hawke-Petit, Komisarjevsky implied he sexually assaulted Michaela and told Hayes to "square things up" by sexually assaulting Hawke-Petit, Dearington said, referring to Hayes' alleged confession.
Hayes told another inmate he poured gas on the stairs, according to testimony, but Dearington said it wouldn't make sense for him only to pour gas on the stairs. He reminded the jury of testimony that gas was poured on or around the victims and that gas was found on the clothes of both men.
Dearington also told the jury that evidence showed Hayley suffered burn injuries from the fire after she managed free herself and made it to the hallway. She died of smoke inhalation.
Hayes had several opportunities to end the crime before the victims were killed, Dearington said, citing the time when he went to get the gas and when he took Hawke-Petit to the bank.
"What's tragic is Hayes could have walked away at any time," Dearington said. "Count the opportunities he had to walk away from this."
Dearington rejected Hayes' explanation that "things got out of control."
"They were out of control. It wasn't things," Dearington said.