Wait, is citizen’s arrest really a thing??
Well, yes. But be careful with that…
Arizona Revised Statutes (A.R.S.) §13-3884 states:
13-3884. Arrest by private person
A private person may make an arrest:
- When the person to be arrested has in his presence committed a misdemeanor amounting to a breach of the peace, or a felony.
- When a felony has been in fact committed and he has reasonable ground to believe that the person to be arrested has committed it.
So it has to be a misdemeanor that breached the peace or a felony and you know who did it.

A.R.S. §3889 requires you to announce the arrest…unless you don’t have to:
13-3889. Method of arrest by private person
A private person when making an arrest shall inform the person to be arrested of the intention to arrest him and the cause of the arrest, unless he is then engaged in the commission of an offense, or is pursued immediately after its commission or after an escape, or flees or forcibly resists before the person making the arrest has opportunity so to inform him, or when the giving of such information will imperil the arrest.

Clear enough?
No. Not at all.
There’s more:
13-3900. Duty of private person after making arrest
A private person who has made an arrest shall without unnecessary delay take the person arrested before the nearest or most accessible magistrate in the county in which the arrest was made, or deliver him to a peace officer, who shall without unnecessary delay take him before such magistrate. The private person or officer so taking the person arrested before the magistrate shall make before the magistrate a complaint, which shall set forth the facts showing the offense for which the person was arrested. If, however, the officer cannot make the complaint, the private person who delivered the person arrested to the officer shall accompany the officer before the magistrate and shall make to the magistrate the complaint against the person arrested.

So, next you need to take the person you arrested to an officer and explain what happened. Then, you need to explain it to the judge. Apparently you shouldn’t make a citizen’s arrest if you’re in a hurry.

Or angry.
The Arizona Attorney General interpreted the provisions in Attorney General Opinion I85-048. It concluded that a citizen making an arrest could be charged with a crime or be sued for false arrest, false imprisonment, assault and battery, negligence, and violation of civil rights. The opinion notes that the provisions have been applied to the actions of security guards and law enforcement outside their jurisdiction.
Nevertheless, the provisions remain a part of Arizona law, where they’ve been since 1939 (Arizona Code §44-125). It seems that this law isn’t going anywhere.