Kansas City Chiefs linebacker Jovan Belcher fatally shot his girlfriend before committing suicide at the NFL team's stadium on Saturday.
Belcher, 25, is believed to have shot himself outside Arrowhead Stadium in a shocking murder-suicide as his coach and general manager attempted to stop him.
Police have identified Belcher's 22-year-old girlfriend, Kasandra M Perkins, who sustained several gun shots at the couple's residence and was pronounced dead after she was taken to hospital.
Belcher's mother was visiting the couple and their three-month-old daughter and is being questioned by police after witnessing the shooting.
Belcher then thanked general manager Scott Pioli and Romeo Crennel before shooting himself in the parking lot of the team's training facility.
Chiefs chairman Clark Hunt confirmed the double shooting and said the club was reaching out to everyone affected.
"We can confirm that there was an incident at Arrowhead earlier this morning. We are cooperating with authorities in their investigation," a club statement read.
"The entire Chiefs family is deeply saddened by today's events, and our collective hearts are heavy with sympathy, thoughts and prayers for the families and friends affected by this unthinkable tragedy.
"We sincerely appreciate the expressions of sympathy and support we have received from so many in the Kansas City and NFL communities, and ask for continued prayers for the loved ones of those impacted."
The Chiefs are scheduled to play the Carolina Panthers at Arrowhead Stadium on Sunday and the league has told the travelling side to make the trip, with no official announcement made yet.
Born in West Babylon, New York, Belcher signed with the Chiefs as an undrafted free agent and has started 10 of the Chiefs 11 games this season, his fourth in the NFL.