DENVER, Colo. -

Officials are dedicating a memorial in honor of a police officer who was shot to death while trying to break up a disturbance during a crowded concert at a Denver park.

Denver Mayor Michael Hancock, Executive Director of Safety Stephanie O'Malley and Denver Police Chief Robert White will gather for the ceremony at City Park on Tuesday with family members of Celena Hollis.

Rollin Oliver is serving a 26-year prison sentence after pleading guilty to second-degree murder in Hollis' death. His lawyers have said he was being chased by gang members when he drew his weapon.