> Citizens in California are allowed to make a citizen's arrest including use of reasonable force.

For a misdemeanor (as the shoplifting described in this case appears to be), only if the arrested party actually committed the offense and it occurred in the arresting party’s presence (for a felony, the terms are somewhat looser.)

As the description clearly indicates that the offense did not occur in the poster’s presence and he wasn’t even aware of the offense until after using force to restrain his victim, he committed both battery and false imprisonment by violence, the latter of which is a felony offense, and the former is at a minimum a violent misdemeanor.

I judged the given probability P(crime | guy being chased in the streets & SF) as much higher than chance, which is what led me to yield to instinct.

I realize that I was over my head considering the guy was much bigger than me and I had no way of knowing if he was armed or not, but I sleep better at night knowing I did what I could to act as a decent human being.

Because I was raised to do what I can to help people in need, who was very obviously not the guy running away, smiling, from two people who looked very distraught.

> manufactured using slave labor.

You’re grasping here. Nice bait.

Check out this analysis of American action movies. It may change the way you see Batman and other characters that may have influenced your thinking.

https://www.youtube.com/watch?v=tOMiAeRwpPA

What do the courts mean by "in the presence?" Although they have not had occasion to elaborate much, they have said that the crime must have been "apparent to the senses," but that this requirement should be interpreted "liberally." Thus, it will be satisfied if the citizen was aware of circumstances from which he could reasonably infer that a crime was occurring in his presence

- https://le.alcoda.org/publications/files/CITIZENSARREST.pdf

I think this would qualify as committing the crime "in the presence" of the above commenter. Running away is part of the theft and that was done in the presence of the commenter.

> What do the courts mean by "in the presence?"

Even the most liberal definition doesn’t include the arrestor being only aware of the crime after the arrest (even the looser felony citizen arrest rules require both knowledge of the offense and reasonable belief that the arrestee committed it, as well as, as in the misdemeanor case, actual guilt.)

I guess we'll just have to agree to disagree here. I think it is perfectly obvious that if you witness theft taking place then the crime is taking place "in your presence".