A 63-year-old Hillcrest Heights woman was killed yesterday afternoon when her car was struck by a patrol car driven by a Prince George's County police officer, county police said.

Police said Bessie Mae Tucker of 2604 Colebrooke Dr. was killed in the 4 p.m. accident in the 2300 block of Iverson Street in Hillcrest Heights. Witnesses said that Tucker's car was struck broadside by the police car and crashed into a tree as she pulled out of the Hillcrest Heights Shopping Center parking lot.

Police said an officer not involved in the accident tried unsuccessfully to revive the woman. Her body was taken to the state medical examiner's office in Baltimore for an autopsy.

Other than saying that the officer was responding to a request for help from another officer who was trying to arrest a theft suspect, police still had little additional information early today to release about the accident.

Officials declined to identify the officer involved, pending completion of their investigation, but said he was not using emergency lights or a siren at the time of collision.

Police spokesman Cpl. Ron Smith said last night that not using emergency lights or sirens violates department policy only if police are responding to a "priority" call. "Preliminary indications" seem to show that the officer was on a nonpriority call at the time of the accident, he said.