Two Connecticut men charged with killing a woman and her two daughters in a 2007 house invasion inflicted unimaginable terror on a model family that had enjoyed their final pleasant summer day together, prosecutors told a jury during closing arguments Friday.

Prosecutor Gary Nicholson said it was impossible to recreate the fear the two girls, 11-year-old Michaela and 17-year-old Hayley Petit, felt when the men tied them to their beds and poured gasoline on or around them before setting their Cheshire house on fire.

"Hayley and Michaela Petit knew that the end was near," Nicholson said. "They knew they were about to die."

The jury in New Haven will begin deliberating Monday in the trial of Steven Hayes, who along with Joshua Komisarjevsky is accused of killing the girls and their mother, Jennifer Hawke-Petit. The girls' father, Dr. William Petit, was beaten with a baseball bat and tied up in the basement, but managed to escape and make it to a neighbor's house to get help.

If Hayes is convicted, the same jury will consider whether he should receive the death penalty in a separate penalty phase. Komisarjevsky will be tried next year.

Tom Ullmann, Hayes' attorney, said in his closing argument that it was Komisarjevsky who began the violence by attacking Dr. 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.

Ullmann acknowledged Hayes sexually assaulted and killed Hawke-Petit, but he said Komisarjevsky was the one in control and had the motive to kill the girls because he had sexually assaulted one of them and had poured bleach on her clothes to try to eliminate his DNA. At one point, he described Hayes as a petty thief.

He said prosecutors had not proven Hayes intended to kill the girls and urged the jury to consider a lesser charge such as manslaughter in connection with the girls' deaths.

"The sociopath or psychopath in this case is Joshua Komisarjevsky, not Steven Hayes," Ullmann said.

Ullmann suggested Hayes could have been intimidated by Komisarjevsky, saying Komisarjevsky was walking around with the baseball bat that he had already used to attack Dr. Petit.

But prosecutors said there was no evidence of any violence between the men and told the jury that both suspects were equally responsible. Nicholson said that both men tied the girls to their beds and that Hayes bought the gasoline and poured it on the stairs, which would have been their only escape route.

"If he didn't like violence, why didn't he leave?" Nicholson said. "He didn't leave because he would do anything for money. You have a consistent effort between the two at every stage to get this money and destroy the family."

State's Attorney Michael Dearington called the crimes a "joint venture" and described how a robbery turned into a triple murder.

Dearington said it all began on 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." Hayley had been accepted into Dartmouth and both girls were active raising money to fight multiple sclerosis which their mother, a nurse, suffered, Dearington noted.

"What was a vibrant house became a house of terror and horror," Dearington said.

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, 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.

Dearington said the 47-year-old Hayes "brutally raped" Hawke-Petit and that the evidence suggested 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 charred 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.

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 to free herself and make it to the hallway.

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.