Patrolman Koch was shot and killed as he and other officers attempted to arrest a bootlegger who had jumped bail. Patrolman Koch and his partner approached the suspect and his wife as they returned to their car. The suspect pulled out a .45 caliber revolver and fired as Patrolman Koch attempted to grab it.

Both officers returned fire, wounding the suspect and his wife. They were both taken into custody. The suspect was convicted of manslaughter and sentenced to 8 years in prison November 9, 1926.

Patrolman Koch had served with the agency for 4 years. He was survived by his wife, 2-year-old son, and parents.