Updated

A 17-year-old girl who died in a gruesome home invasion that also killed her sister and mother likely took up to several minutes to die of smoke inhalation after her house was doused in gasoline and set on fire, a medical examiner testified Monday.

Dr. Malka Shah could not say if burns found on Hayley Petit's body occurred before or after she died. Shah testified in the trial of Joshua Komisarjevsky, who faces a possible death sentence if he's convicted. His co-defendant, Steven Hayes, was convicted last year and is on death row.

Hayley had been tied in her bed and left to die in the fire that prosecutors said both men set, but her body was found at the top of the staircase. Her 11-year-old sister, Michaela, also died of smoke inhalation in her bed. The girls' mother was raped and strangled.

Hayley's clothes smelled of gas, she had remnants of rope tightly tied on her, burns all over her body and her lungs were filled with carbon monoxide, said Shah, of the chief medical examiner's office. Inhaling smoke and hot air would have been painful and such deaths can take anywhere from a few to several minutes, Shah said.

Shah said she could not say whether the burns occurred while Hayley was alive, nor could she say if the injuries occurred before or after Hayley fell in the hallway.

If the death had taken several minutes, Hayley would have fallen unconscious at some point, she said under cross-examination. But before that, victims typically suffer headaches, nausea, vomiting and disorientation, she said.

Jurors were shown the autopsy photos and a few fought back tears.

Authorities say Komisarjevsky and Hayes broke into the house in Cheshire in July 2007, beat Dr. William Petit with a bat, then tied him, his wife and two daughters up as they looked for money. Hayes later drove the woman, Jennifer Hawke-Petit, to a bank so she could make a withdrawal and then raped and strangled her after they returned to the house, police said.

Komisarjevsky and Hayes have blamed each other for escalating the violence, but prosecutors say both men are equally responsible.

William Petit, who was tied up but managed to escape to a neighbor's house to get help, left the courtroom before the autopsies were detailed. His sister wept and left the courtroom later.

Earlier Monday, Detective Joseph Vitello testified that Komisarjevsky initially told investigators that he may have poured gasoline before the house was set on fire. That testimony undercut efforts by Komisarjevsky's lawyers to blame Hayes for pouring the gas.

Vitello also told jurors that Komisarjevsky took explicit cellphone photos of Michaela Petit, whom he has admitted molesting. Komisarjevsky planned to send the photos to Hayes so that he could show them to the girl's mother if she didn't cooperate while the two were outside the home.

Komisarjevsky gave an audiotaped confession that was played to jurors last week. In it, he said he spotted Michaela and her mother at a supermarket, followed them home and later returned with Hayes.

Prosecutors showed photos taken by a video camera of Hawke-Petit and Michaela at the supermarket shopping for what turned out to be the family's last meal together. Michaela appears to be looking back at her mother in one photo. In another, taken in the produce section, she has an item up to her face that she apparently is eating or smelling.

Prosecutors also showed photos from the video camera of Komisarjevsky and a contractor he was collecting a payment from near an ATM at the supermarket. Komisarjevsky was in the store around the same time as Hawke-Petit and her daughter, according to testimony.

Komisarjevsky's attorneys tried to show the jury he immediately cooperated with police by telling them two girls were in the house engulfed in fire, while Hayes offered no help.

But Vitello said Komisarjevsky was quick to implicate Hayes, while not revealing some details of his own role.