Actual impersonation. From a CNN article:

Around 3:35 a.m., another call came in when officers were proactively checking on Hortman’s home. When Brooklyn Park police officers arrived they noticed that there was a police vehicle in the driveway with emergency lights on and what appeared to be a police officer at the door, coming out of the house, officials said. That individual immediately fired a weapon at them, Evans said, and exchanged gunfire took place during which the suspect was able to escape.

https://edition.cnn.com/2025/06/14/us/minneapolis-targeted-shooting

I don't think a cop doing this would shoot back at other cops. They'd report back that the perp was long gone and they saw nothing.

Edit: lol, the guy is a rent-a-cop