(CBS) - Kansas City Chiefs linebacker Jovan Belcher argued with his girlfriend Kasandra Perkins over their baby's paternity before he fatally shot her in their Missouri home and then himself, the New York Post reported on Friday.
Belcher's mother, Cheryl Shepherd, told investigators that there were questions about whether her son was the biological father of the couple's 3-month-old daughter, Zoey, a source told the Post under condition of anonymity.
"The mother believed that there was an issue over whether [Belcher] was the father," said the source. Belcher believed he "wasn't necessarily the father of the child."
It is uncertain whether the paternity issue was the reason why 25-year-old Belcher shot 22-year-old Perkins nine times on Dec. 1, the Post reported. Sgt. Marisa Barnes said the baby's paternity will not be part of the Kansas City police department's investigation into the murder-suicide.
"That would not be something they're going to investigate," Barnes said. "It's a 'he-said, she-said' so there's no way to investigate. It would be nothing more than a civil matter."
Police said that after shooting Perkins, Belcher drove to his team's practice facility at Arrowhead Stadium where he thanked general manager Scott Pioli and coach Romeo Crennel for all they'd done for him. He then shot himself in the head.
Belcher and Perkins met through her cousin, Whitney Charles, who is married to Chiefs player Jamaal Charles. Perkins started dating Belcher in 2010 and gave birth to Zoey this September, according to the Post.
The couple's relationship was rocky, and Perkins went to visit her family in Texas around Halloween, the Post reported. The couple lived apart briefly but had gotten back together by Thanksgiving.
While Shepherd has temporary custody of the baby, a permanent guardian has not been named, according to the Post. But Perkins' family indicated that they will be involved in the child's upbringing.