[Rule10b5]

A "citizen's arrest" is legal in Pennsylvania.

Actually, this very issue was recently reaffirmed by the Pa. Supreme Court. See Kopko v. Miller, 586 Pa. 170, 185 (Pa. 2006). The thing is, it only works for certain types of offenses (felony and other limited classes too complicated to get in to) personally witnessed by the citizen.

As an aside, there is a misconception about what an "arrest" actually is. An "arrest" is any "seizure" of a person. A person is "seized," in brief, whenever you're telling him that he can't leave. So, if someone tries to shoot you, you disarm him and hold him at gunpoint, while waiting for the Police to arrive, you've arrested him.

This is different from a formal or agency arrest (like the one that Steve would execute) where he formally takes the person into the custody of the institution and begins the process of filing formal charges. (I think this what your post means, Steve).

The distinction isn't really important -- the point is that you're technically "arresting" someone when you engage in the above behavior. You needn't say any nonsense about "I'm placing you under citizen's arrest" or any bullshit like that. Your actions create the end result of an arrest, basically.

(As a total random and unrelated "isn't it cool" sort of fact: Courts (I don't know whether in Pa.) regularly hold that a person may be prosecuted for resisting an arrest by a citizen, provided that the arrest itself is valid and executed in good faith.)

Relevant portions of the above referenced case follow (emphasis added by me):

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"We note that the power of Sheriffs to arrest for crimes committed in their presence is no different from that of a private citizen. In Commonwealth v. Chermansky, 430 Pa. 170, 242 A.2d 237, 239 (Pa. 1968), we reiterated that "a private person [***24] in fresh pursuit of one who has committed a felony may arrest without a warrant. And in Pennsylvania we have [**775] always followed the common law rule that if the felon flees and his arrest cannot be effected without killing him, the killing is justified." However, we narrowed the types of felonies for which the rule was applicable and held that:

from this date forward the use of deadly force by a private person in order to prevent the escape of one who has committed a felony or has joined or assisted in the commission of a felony is justified only if the felony committed is treason, murder, voluntary manslaughter, mayhem, arson, robbery, common law rape, common law burglary, kidnapping, assault with intent to murder, rape or rob, or a felony which normally causes or threatens death or great bodily harm.


Id.at 240. See Commonwealth v. Corley, 316 Pa. Super. 327, 462 A.2d 1374, 1379 (Pa. Super. 1993) ("we hold that a citizen's arrest can be made for a breach of the peace that is personally observed by the arrestor."), aff'd on other grounds, 507 Pa. 540, 491 A.2d 829, 834 (Pa. 1985) (declining to rule on the issue).
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