SOUTH SALT LAKE — David Partridge knew right away it was a cry for help from his daughter.

On Saturday, while going through a notebook of drawings belonging to his granddaughter, Partridge found a four-page handwritten letter from his adult daughter, Tracie Williamson, stuffed between the pages. The note outlined Williamson's turbulent relationship with her live-in boyfriend, Peter Perez, who, with his explosive temper, threatened several times to kill her, her daughter and her family.

"It's in her writing. A desperation letter for someone to step in and get her away from him because he threatened her life," Partridge said in tears outside his West Jordan house Tuesday.

Monday night, Williamson, 28, her daughter, 10-year-old Linzie Williamson, and her boyfriend's 1-year-old daughter, Jessica Perez, were found dead inside Williamson's home. All were shot multiple times. Also in the house, police discovered the body of Peter Perez, dead of a single gunshot wound, and a suicide note. Detectives believe Perez killed the others before shooting himself. Investigators were unsure Tuesday how long the victims had been dead.

"It's unreal. You hear people on the TV say, 'I didn't think this would happen to my family.' And you just think, 'It'll never happen to my family,"' said Natalie Cleverly, Tracie Williamson's older sister.

For nearly a year, Partridge said, he did all he could to get his daughter away from Perez. His daughter told him she was scared to death of Perez, he said. In the letter, Williamson wrote that Perez threatened to "chop (Jessica) into little pieces" and if Williamson went to her family or police for help for the mental and physical abuse she was suffering, he would kill her.

"He made threats against me, he made threats against my mom, saying that if they call the police one more time that my mom would find herself in the back of a Lincoln," Cleverly said.

Partridge assumes the letter was written four or five weeks ago.

"She said she was really scared for her life," Partridge said.

So scared, family members say, that Tracie never went to police for help. Although police were called to Williamson's house a few times over the past year for non-domestic violence related matters, and an officer once questioned Williamson about possible domestic violence, according to her father, she never filed a domestic violence report with police or sought a protective order.

"He basically scared her into staying with him. She was afraid to leave him," Cleverly said.

Whenever the family tried to talk to Williamson about Perez's threats, she would brush them off and try to convince them he didn't really mean what he was saying, Cleverly said.

Ironically, the only protective order ever taken out was by Perez, who said a former girlfriend was abusing him, according to police.

Partridge called police Saturday to have them do a welfare check on his daughter at her house, near 2400 S. West Temple. No one answered the door. But because there were no signs of forced entry or evidence that a crime had been committed, officers couldn't break the door down and enter, said South Salt Lake Police Chief Chris Snyder.

Monday night, Cleverly called police to request a second welfare check.

"We had worried throughout the week because we had had no contact with Tracie. Linzie wasn't in school. At that point we were extremely concerned," she said.

Cleverly met detectives at the house, and they again did not find anything suspicious, Snyder said. But because this was the second time they had been called to the house, officers decided to pry open a window and look inside. Immediately they could smell a foul odor and then they spotted one of the four bodies inside, Snyder said. Detectives believe the victims had been dead for some time.

The secluded house where the bodies were found is the lone home in the middle of an industrial area. The house is on the property of a coffee distributing business and was rented to the family. Managers of the coffee business declined comment Tuesday.

Many retailers in the area say they were shocked to learn children were living in the house. They said the house always looked the same as it did Tuesday, with the window shades drawn and the grass overgrown.

"I never saw kids outside playing, I never saw the curtains open, I never saw a porch light on, there was never activity there at all," said Priscilla Lister, who works at Studio il Bagno.

"I couldn't believe they lived in their house," said Jenica Love, who works at Poliform, across the street from where the bodies were found.

Even when she worked on Saturdays, Love said, she never saw much activity at the house.

"It's so sad. I can't imagine that happening to anybody," she said. "You never saw them in the yard playing. No cars ever pulled up front. Just to have that happen to the kids ... It's sad."

Williamson also had a 7-year-old daughter. But just recently, Partridge said, he forced his daughter to sign over guardianship of that child to him. That daughter was living with Partridge when the slayings occurred. He said he was in the process of trying to get guardianship of Linzie when the tragedy happened.

Partridge said he wanted to share his family's story Tuesday in hopes that it might encourage others who feel like they are trapped in an abusive relationship to seek help.