ANGOLA, Ind. (AP) — State Police are hoping the public can help them solve the only unsolved killing of a northeast Indiana police officer.

Fremont Town Marshal Bobby Moore was gunned down on July 26, 1988, outside his home in the town that’s just south of the Michigan state line.

State Police Detective Commander Kevin Smith believes someone knows something about Moore’s killing 30 years later.

He tells The (Angola) Herald-Republican that person needs to “do the right thing” and give authorities information that can help solve the case.

The passage of time often works against cold case investigators, but Smith says that in some cases time can make some people more willing to talk to police about unsolved crimes, either due to guilt, remorse or a simple decision that it’s time to talk.