(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.

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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.

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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.

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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.