HOUSTON/FAYETTEVILLE, Arkansas (CBSDFW.COM) — Two police officers were shot and killed in the line of duty only hours apart from each other Saturday night.

Around 6 p.m. Saturday, Houston Police Sgt. Christopher Brewster was shot after trying to break up a domestic disturbance. He died about half an hour later at a nearby hospital.

Sgt. Christopher Brewster (Houston Police Department)

A few hours later around 9:42 p.m. in Fayetteville, Arkansas, Stephen Carr was sitting in a patrol vehicle outside his police station when he was shot and killed.

Evidence showed that Carr was ambushed and executed while sitting in the vehicle by a suspect who police say was looking for an officer to kill.

Stephen Carr (Fayetteville Police Department)

Houston and Fayetteville are less than 600 miles apart.