Police have released photos of a man who they say assaulted a traffic agent after urinating on an NYPD tow truck.

The incident happened at about 6:30 p.m. Wednesday on East 39th Street near Madison Avenue.

According to police, the traffic agent witnessed a man peeing on the tow truck. When the agent tried to approach the man about urinating on the truck, he was punched in the face.

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A driver tried to help the agent, identified as Jude Maxwell, 52, but another man on the street helped the attacker escape, according to the New York Post. He was arrested, but the man who punched Maxwell is still at large.

Police describe him as a man in his 50s who was wearing a red tank top.

Local 983, the union which represents traffic enforcement agents, has offered a $500 reward to anyone with information leading to the arrest, the Post reported. Maxwell reportedly suffered swelling and nearly dislocated his jaw.

“[Traffic agents] feel like because they’re not police officers they can be victimized,” Local 983 president Joseph Puleo told the Post.