Friends and family gather at the home of slain Denver Police Officer Celena Hollis, on Monday, June 25, 2012, in Denver. Hollis was shot and killed during a free jazz festival, on Sunday. A suspect, Rollen Oliver, was taken into custody late Sunday after witnesses gave a description of the gunman. Police also recovered a gun and said they believe Oliver was the only person involved in the attack. Police Chief Robert White said investigators were not sure if Hollis was the target of the shooting when she answered a call about a disturbance in the park. (AP Photo/The Denver Post, Cyrus McCrimmon) MAGS OUT; TV OUT; INTERNET OUT

DENVER | A funeral is scheduled Saturday for Denver policewoman who was shot and killed at a city park where families had gathered for a free weekly jazz concert.

Friends and family gather at the home of slain Denver Police Officer Celena Hollis, on Monday, June 25, 2012, in Denver. Hollis was shot and killed during a free jazz festival, on Sunday. A suspect, Rollen Oliver, was taken into custody late Sunday after witnesses gave a description of the gunman. Police also recovered a gun and said they believe Oliver was the only person involved in the attack. Police Chief Robert White said investigators were not sure if Hollis was the target of the shooting when she answered a call about a disturbance in the park. (AP Photo/The Denver Post, Cyrus McCrimmon) MAGS OUT; TV OUT; INTERNET OUT

Officer Celena Hollis was shot Sunday night while responding to a disturbance. Hollis was a 32-year-old single mother and a seven-year Denver police veteran who previously worked as a Detroit police officer.

Police have arrested 21-year-old Rollen Oliver on suspicion of first-degree murder.