At about 10 p.m. on Feb. 28, Boone County Sheriff’s Department deputies arrived at 4426 Santa Anna Drive to find two victims killed and one wounded, according to the department’s news release.

Upon investigation, deputies found 53-year-old Deborah Koontz and her brother, 51-year-old Donald Wilson, who were pronounced dead at the scene. Willie Mays, 44, was taken to a local hospital with a gunshott wound to the head.

Witnesses gave deputies a description of the suspect and vehicle used to flee the scene. The deputies spotted and began chasing the vehicle heading west on Highway WW and El Chaparral Avenue. Cornelius Parker, 28, was suspected in the shooting.

While attempting to turn south on US Highway 63 from Broadway, the suspect lost control of the vehicle, according to the release. Once the suspect exited the vehicle, he began shooting at the deputy with a handgun.

The 32-year-old deputy shot back, killing Parker. The deputy was not injured.

There is currently no known motive. The three victims, as well as Parker, all resided where the shootings took place.

The deputy who killed Parker has over 11 years of law enforcement experience, according to the release. He is an Enforcement Sergeant, a firearms instructor and a 10-year veteran of the Special Weapons and Tactics team. He’s had over 1,000 hours of tactical training.

The Missouri State Highway Patrol’s Division of Drug and Crime Control is investigating the deputy’s shooting of Parker. The Boone County Sheriff’s Department is investigating the original shooting of Koontz, Wilson and Mays.