Brian Nicholson, Associated Press
Terri Cook, mother of Lacey Lawrence, cries during sentencing trial.

FARMINGTON — Terri Cook stared into the eyes of the man who killed her 6-year-old daughter and sobbed as she told him, "You've ruined my life."

Lacey Lawrence was her sunshine, her reason for living. Cook hasn't been able to hold down a job or have a steady relationship since the day Mark Anthony Ott burned down the house Lacey was sleeping in on Sept. 1, 2002.

"I have to go home tonight without my daughter," Cook testified Tuesday at the third day of Ott's sentencing trial. "I have to live alone for the rest of my life and be unhappy for the rest of my life. I hope you understand that."

Ott was in court Tuesday for a jury trial to determine whether he gets life in prison with or without parole. Earlier this month, Ott accepted a plea bargain that ruled out the death penalty. The prosecution ended its case Tuesday with a video presentation depicting pictures Lacey had drawn, home video and still photos of the young girl. Although brief, the video had most of the courtroom, including jurors, in tears.

The defense will continue its case today.

Lacey was in her first week of the first grade when she died. She was sleeping upstairs in Ott's then-estranged wife's home in Layton when Ott broke in, stabbed two people repeatedly, doused furniture with gasoline and set the house ablaze.

Two adults and three teenagers then fled the home, but Lacey was trapped inside. Dr. Maureen Frikke of the State Medical Examiner's Office said Lacey died after inhaling the products of an extremely hot fire, including soot, hot gases and carbon monoxide.

The blaze left the scorched outline of her body on the bed.

Lacey was staying at the house that night with her father, Allen Lawrence, who was dating Donna Ott at the time. It was the first night Lacey had ever slept over.

Defense attorneys contend Ott did not know Lacey was inside the house when he started the fire. But her older sister, 18-year-old Amber Lawrence, said it did not matter.

"Mark does not care if it was me, or my sister or everybody in that house," Amber Lawrence said. "He burnt it down. He didn't help anyone out of it."

Memories of the attack forced 16-year-old Lucy Gooch, daughter of Donna Ott, to move out of her mother's house in November. She recently moved back in.

"You couldn't live a day without being reminded of it," Gooch said. "I just couldn't take it anymore."

Amber Lawrence was an honor student before her little sister, Lacey, was killed. Now she is struggling to graduate with her class and is attending night school.

She stutters and said she has developed attention deficit problems she never had before.

"I can't find the right words to say when I talk. I can't concentrate," Amber Lawrence said. "It's hard to say what I go through every day, but I'm here."

Prosecutors called multiple witnesses who told the jury that Ott should remain in prison for the rest of his life.

Amber Lawrence said she was scared sitting just rows behind Ott, and her fears were heightened because he wasn't wearing handcuffs.

Gooch said for the first little while after the incident, there was no possible way to fall asleep without having a nightmare about Ott. Those nightmares creep back every now and then.

"I think that if we let him out, it doesn't matter if it's 20 years, he'll finish what he went there to do," Gooch said.

While in the Davis County Jail, Ott threatened inmates and supervisors often and was classified as a "problem inmate," said Sgt. Wayne Callister of the Davis County Sheriff's Office.

"He was a behavioral problem from day one," said Capt. Bob Yeaman, division commander for all jail operations for the Davis County Sheriff's Office. "I have never met anyone who was more of a behavioral problem than Mr. Ott."