NASHVILLE, Tenn. - Sahel Kazemi was determined to be with her boyfriend, former NFL star Steve McNair — even in death.

As he dozed on a sofa early Saturday, Kazemi shot him in the head, then twice in the chest, then again in the head.

Before shooting herself, the 20-year-old sat next to his body and “tried to stage it so she would fall in his lap,” Police Chief Ronal Serpas said Wednesday at a press conference where police confirmed the deaths were a murder-suicide. She did, but her body slid to the floor and ended up at McNair’s feet. The gun was found underneath her.

Serpas said police believe McNair was asleep when he was killed.

Interviews with friends revealed that Kazemi “was spinning out of control.”

She was making payments on two cars, her rent was doubling and she suspected the married McNair was having a second affair with another young woman.

She told a friend on Friday that “My life is a ball of s--- and I should end it,” Serpas said.

Police earlier had labeled McNair’s death a homicide, but waited for further tests before concluding that she pulled the trigger of a 9 mm semiautomatic pistol in a condominium McNair rented with a friend.

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McNair, 36, a quarterback for the Tennessee Titans most of his career, met Kazemi six months ago at a sports cafe where she was a waitress and his family often ate. She seemed happy and eager to build a life with him, but something went wrong.

“We do know that she was clearly sending a message during the last five to seven days of her life that things were going bad quickly,” Serpas said, though there was no indication she told anyone she planned to harm McNair.

Serpas said detectives learned that Kazemi recently found out about another young woman she thought McNair was romantically involved with and had even followed that woman home, though she did not confront her.

Kazemi’s family told reporters that the woman was so confident McNair was divorcing his wife of 12 years that she was preparing to sell her furniture and move in with him.

But Mike Mu, who has worked with McNair’s charitable association for years, said earlier Wednesday that McNair’s wife, Mechelle McNair, “didn’t know who this girl is.” No records of divorce proceedings have surfaced. The McNairs have four children.

Two days before the shooting, police stopped Kazemi driving a Cadillac Escalade sport utility vehicle that McNair had given her for her birthday in May.

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According to an arrest affidavit, Kazemi had bloodshot eyes and alcohol on her breath. She refused a breath test and told an officer “she was not drunk, she was high.” She was charged with DUI. McNair was with her but not charged. He later made her bail.