On the evening of June 24, 2012, off-duty Denver Police Officer Celena Charise Hollis, 32, was working at a jazz festival in City Park when a fight erupted near the pavilion by City Park Lake. Officer Hollis went to intervene to de-escalate the confrontation and was struck in the head by a bullet shortly after 8:00 p.m. She was taken to Denver Health Medical Center, where she died of her wounds. She left behind a 12-year-old daughter.

Hollis had served with the Detroit Police Department for four years before joining the Denver Police Department in 2005. In Denver she was president of the Denver Black Police Officers Organization and mentored high school girls, remembered as a respected member of the department and community.

A 21-year-old, Rollen Oliver, was arrested late the night of the shooting after witnesses provided a description and police recovered a handgun. He was initially charged with first-degree murder; court testimony later described Oliver saying he fired a gun over his shoulder while fleeing an assault, and ballistics matched a bullet from his gun to the fatal shot. Oliver pleaded guilty to second-degree murder and received a 26-year prison sentence.

Did anyone at the festival or in the area that night see the fight escalate or the moments before the shooting?