(CBS) — An off-duty police officer in Racine, Wisconsin, was shot and killed Monday night, after witnessing an armed robbery at a bar.

Officer John Hetland waw an armed robbery in progress around 9:40 p.m. at Teezer Tavern, and stepped in to stop it. That’s when he was shot and killed.

Racine Police Officer John Hetland (Source: Racine Police)

Hetland, a 24-year veteran of the Racine Police Department, had been on patrol on the day shift earlier Monday.

The Kenosha County and Racine County sheriff’s departments were investigating, alongside Wisconsin State Patrol and the state crime lab.

The Kenosha County Sheriff’s Office released a surveillance video image of the suspect, who was wearing a hoodie and a mask.

No one was in custody Tuesday morning, and police have not provided a description of the suspect or suspects.

Police said anyone with information about the robbery and shooting should call the Kenosha County Sheriff at 262-656-1234, or Crime Stoppers at 888-636-9330, 262-656-7333 or (800) 807-TIPS (8477). Tipsters can remain anonymous. Police also asked anyone with outdoor cameras to review their footage and contact authorities with anything suspicious.