If one were to witness a police officer in the act of committing a crime, would it be possible/legal to perform a citizen’s arrest on him or her?
Does it matter what kind of crime was witnessed – e.g. whether the officer was murdering an unarmed civilian or merely taking a bribe?
What would you do after the arrest? Call 911 and have other police come, probably getting beat up in the process? Talk to Internal Affairs?
Has this ever been tried?
He’s got several weapons at his disposal and is trained in their use.
If he’s murdering someone,he won’t stop just because you try to arrest him, he’ll have no problem murdering you. If you are armed and can get the drop on him, that’s about your only chance of success.
Pretty much anything else, get evidence if you can and go to Internal Affairs.
Need answers fast?
Let’s for the moment ignore the physical challenges and focus on the legal/philosophical ones.
Previous thread:
Could a citizen put an on duty police officer under citizens arrest?
I thought about including that thread but it doesn’t really answer the question and ends on a cliffhanger about reasonable grounds. Hopefully we’ll have some new, better replies after six years 
Username/post appropriateness?
There’s no reason to believe that LEOs are immune to arrest. They enjoy broad protection while doing their jobs, since the job often requires actions that would otherwise be illegal. Physical assault, detaining people against their will, kidnapping, using a firearm, etc. That protection is not unlimited, there are many things they can do that would subject them to arrest.
Functionally, all a citizen’s arrest means is that the person who detains the suspect is not going to be prosecuted for his actions. The person does not have the broad protection that a LEO has, so they could be subject to a suit or prosecution of the arrest was improper. You had better be damn sure the arrest is proper, and you’re not arresting the LEO over something he has legal protection to do.
In reality, it probably isn’t always easy to read the situation correctly. For instance, if you watched a LEO sitting on top of another person and punching that person in the face, making the correct judgement isn’t easy.
On the other hand, if you see a cop shooting at a group of kindergarten kids, the situation seems to be clear.
My nonprofessional opinion is that yes, a citizen’s arrest of a LEO would be substantively legal assuming that the basic criteria for a citizens arrest in the jurisdiction was fulfilled (e.g. the arrest must be for a felony and not a misdemeanor). However, doing so outside of the most obvious and egregious situation would be catastrophic for your reputation. You’d be arrested yourself, and probably charged with everything the officer or prosecutor can think could possibly stick. Then, 2 years and $50,000 later, you’ll emerge from court conviction free, but with no job, no home, and PTSD.
Short answer is, of course you can.
Real world answer, you better be pretty sure of yourself and able to afford a really good lawyer and have a lot of witnesses and friends in the media.
Even if you are a police officer yourself and go by the book:
Imagine what a department could do to a private citizen if they wanted to. All this guy was doing was trying to prove that crime statistics were being manipulated to make the department look good.
Some things to keep in mind. YMMV, but a citizen can only arrest for a felony he witnesses personally, and he must know that the act is a felony. A citizen does not have the right to detain while he determines if a crime was committed. So in your example of the cop taking a bribe, how is it that the citizen is 100% the officer is taking a bribe? Could be receiving money for a number of reasons…
Also, and here is a big one, there is no crime of “resisting citizens arrest”. So if you try to arrest the officer (or anyone for that matter) and they beat your ass, then well… You get your ass beat.
For the purposes of the legal trivia of the OP, why would the citizen need to use force? Simply walk up to Officer Smith, Badge #1234, and tell him that you are placing him under arrest for mopery and he is to obey your commands.
When he gets done laughing his ass off or whatever he does, simply advise him that he is resisting your arrest and direct him again to comply.
When he again refuses (which he will) state that you are submitting to his superior physical strength and weaponry, but believe that your arrest of him is proper and you will be reporting his conduct to the prosecuting attorney for further action. Now, when and if you do that, will the officer be charged with, not only the act you witnessed, but resisting arrest (if the arrest is indeed lawful)?
To sum up, it’s legal, but you can’t do it. If you think I’m wrong, just go try it.
There’s also the issue that interfering with a police officer performing his duties is itself a crime in virtually every jurisdiction in the country. And placing a police officer under arrest would certainly constitute interfering with his ability to perform his duties.
Now, if the police officer had committed some serious felony you can argue that you had good cause to arrest him and he had forfeited his right to act as a police officer by his actions. But be aware the arrests are going to be a two-way event and you’ll end up defending both the legality of your arrest of the officer and the illegality of the officer’s arrest of you.
Yeah, you are pretty much guarenteed to end up getting the business-end of the Night-stick or worse, shot with a Ham Sandwich in your (cold, dead) hand.
I don’t think this is entirely true. I was arrested for DUI by an officer out of his jurisdiction. My lawyer told me that doesn’t matter, because any citizen was allowed to make a citizen’s arrest in that case. Just because he was out of jurisdiction doesn’t mean the cop has fewer rights than Joe Schmoe. This wasn’t a felony, so at least in Illinois I think you can make a citizen’s arrest for misdemeanors.