Reply #31: Your examples are distinguishable from the Horn case in a number of ways.

[Guaranteed]

A couple of things to keep in mind about the Horn case:

1) He apparently had a good vantage point from the safety of his home. To witness what was happening, at least to a good extent, he did not need to leave his home and put himself in danger. In other words, he could have been very effective in bringing about the apprehension of the burglars while remaining in his home (although he may not have gotten the chance to kill someone from there).

2) In the same vein, Horn had already summoned the police, a number of minutes before, and had given them a good description of the suspects. He was not alone, the police were on their way. He did not need to play John Wayne in order to ensure justice.


In your first case, there is certainly nothing wrong with the onlooker becoming involved in the situation to a reasonable extent. Heck, if he had caught the rapists in the act, he most likely would have been justified in shooting them (especially if they already had knives on them, even if he didn't know it- he could have reasonably suspected that they had weapons, considering they were raping this woman). But as far as simply witnessing what he could of the suspects after the fact, there is no reason for him to let the suspects know that he was there, or to put himself in danger- as long as they are leaving. He could have hidden himself and accomplished the same objective in that case, which was apparently to identify the suspects.
While I believe the person in the first example approached the situation incorrectly, and could be criminally liable on some level, what he did was not murder. What that person did NOT do- and this is a HUGE difference between your first example and the Horn case- is form the intent to kill before encountering the suspects. If the suspects were leaving and the witness at that point formed the intent to kill them, and then put himself in their way with no other purpose than to carry out that intent, that is murder, quite arguably of the first degree (although the circumstances, particularly the rape, would likely get the charge reduced). It would be no defense, either, that they drew knives on him once he had already formed the intent and taken steps toward accomplishing it. That is a key difference between your example and the Horn case.

As far as distinguishing your second example, the person being mugged, while he was previously aware that he was in a dangerous neighborhood (there was "a chance," as you put it), he did not have actual notice of any criminal activity or criminals in the area. Joe Horn was well aware of what he was going to encounter when he left his house- in fact, he left his house with the purpose of encountering- and killing- criminals. In your example, the "chance" you refer to does not rise nearly to the level of the Horn case. Not only was the probability of an encounter much higher in the Horn case, given that Horn knew the two suspects were out there, but he intended to encounter- and, again, KILL- them. If the person in your example had been aware of a particular criminal in the area and suspected a high probability of an encounter if he walked down that street, and had previously formed the intent- a plan- to kill this person in such an encounter (under the guise of self-defense, perhaps), then he too, most likely, would be guilty of first-degree murder. But that is not the example you gave us, and in that context, there is no criminal wrongdoing at all.