DENVER (CBS4)– The City of Denver honored a police officer who was shot to death in City Park last summer. Officer Celena Hollis’ name was added to the Denver Police Memorial.

Officers from the Denver Police Department gathered at the memorial located in front of the police headquarters at 13th and Cherokee in downtown Denver Friday morning.

All 69 names of the officers killed in the line of duty were read to make sure their sacrifice is always remembered.

Denver Mayor Michael Hancock was among those paying tribute to Hollis.

“Words will never be enough to express our most sincere gratitude for the ultimate sacrifice they have made nor will they ever be enough to fill the void and great loss their families have experienced,” said Hancock.

Celena Hollis (credit: Denver Police)

Celena Hollis (credit: Denver Police)

Hancock said he recalled answering a question about what his one hope was when he took office. He answered that he hoped he would never have to bury one of the men or women in uniform.

The 32-year-old single mother was gunned down at City Park June 2012. She was trying to break up a fight when she was shot and killed.

The man charged in her death, Rollin Oliver, pleaded guilty to second-degree murder and faces at least 16 years in prison when he is sentenced at a hearing scheduled for June 21.