By Kevin Murphy

KANSAS CITY, Mo (Reuters) - Kansas City Chiefs' linebacker Jovan Belcher told a woman friend he was so frustrated with his girlfriend Kasandra Perkins, that he might shoot her, which he did in a murder-suicide on December 1, according to a newly released police report.

Belcher, 25, was having an intimate relationship with the other woman and told her in a text message around early November that if Perkins didn't leave him alone he would shoot her, the report said. The woman thought the text was a joke.

Belcher shot Perkins, 22, at least ten times after an argument in their house and then turned a gun on himself about 15 minutes later outside the Chief's practice facility as head coach Romeo Crennel, General Manager Scott Pioli and other staff looked on.

Details of the Belcher case are contained in police reports submitted to the Jackson County prosecutor, who has ruled the event a murder-suicide. They include dozens of interviews with witnesses.

Belcher and Perkins, parents of a three-month-old girl, had a stormy relationship, according to interviews police conducted with Belcher's other girlfriend, also 22. She told police that Belcher complained about Perkins threatening to take all his money and the baby if they broke up.

Belcher said Perkins "knew exactly how to press his buttons and make him angry," according to a summary of the woman's interview with police.

Belcher had been with the woman and some of her friends at a downtown Kansas City entertainment district the night before the shooting, the woman said. He spent part of the night in her apartment and part of it sleeping in his car before going home early in the morning, the report said.

Belcher and Perkins were arguing before he shot her, his mother, Cheryl Shepherd, told police. Shepherd had moved in with the couple two weeks earlier to help care for the baby. Shepherd heard Belcher say "You won't talk to me that way" and then she heard a thump and gunshots.

Shepherd rushed into the bedroom and found Perkins laying on the bathroom floor, she told police. Before fleeing the house, Belcher knelt next to Perkins, apologized and repeatedly kissed her, his daughter and his mother, Shepherd said.

Belcher drove off in his Bentley to the practice facility at Arrowhead several miles away, where he pulled into the parking lot and saw Pioli, the report said. Pioli quoted Belcher as saying, "I did it, I killed her." Belcher held a handgun to his own head. "I got to go, can't be here, and take care of my daughter," Pioli recalled Belcher saying.

Belcher had asked to speak with Crennel and linebacker coach Gary Gibbs, the report said. Crennel told police he pleaded with Belcher to put down the gun. One witness said she heard Crennel say, "you're taking the easy way out."

Belcher lowered the gun, but only to load a round into the chamber, Crennel told police. Seeing a police officer in the distance and hearing sirens, Belcher knelt behind a mini-van, blessed himself and fired the gun into his temple, the report said. (Reporting By Kevin Murphy; Editing by Mary Wisniewski, Greg McCune and Andrew Hay)