Investigators are asking for the public’s help in the June 30 death of 47-year-old David Ruth in northern Kansas City. KMBC reports police believe Ruth was shot during a robbery at his home. His firearms were taken and his truck was found abandoned more than 10 miles from his home.

Police say an anonymous donor recently contributed another $2,000 to the reward for information leading to an arrest.

Ruth was the brother of Sgt. Danny Ruth of the Clay County Sheriff’s Office. Danny Ruth says he’s confident the killer will eventually be caught.