I know there is not the proverbial snowballs chance in heck of it actually happening in the history of humanity but…
Lets say Officer Joe is on duty in a marked police cruiser, patrolling a super highway, in a moment of deep thought he inadvertently, slipped a mile per hour above the 75 MPH posted limit. At that time he just happened to pass Officer Bob lying in wait in a speed trap, and he has it on radar 76 mph, - can Officer Bob legally pull over and ticket Officer Joe?
Of course.
Now, the odds of it actually happening are close to zero.
Nut they are not zero. So what I mean to say is: THEORETICALLY, it’s possible, and there is nothing in the law that would prevent it.
It happens.
Legally, there is nothing to prevent it. In fact, it’s more likely that the ‘police professional courtesy’ is violating the law.
But it is quite rare in practice.
The only times I have heard of this was when there was a ‘feud’ going on between the big city police dept. and the small suburb police dept.
I have heard a story of a cop who got pulled over for speeding in his cruiser and ended up working the front desk for a month. Of course, in this story, he was just racing around with the light-and-sound show running, and that is likely frowned apon.