I don’t know why but I just thought about it!
What if the person isn’t guilty of anything and you injure them? Guessing a lawsuit could be filed.
Many years ago, DH stopped a purse snatcher by sticking his foot out, to trip him on a subway platform. When DH turned around, there were 2 cops already on the guy. They proceeded to both thank and admonish DH, because if they weren’t there, it could have gotten pretty ugly. The woman whose purse was taken was very grateful, and she wrote a nice thank you to DH’s boss, explaining why he was late getting to his office the day before.
Innocent until proven guilty
Innocent until proven guilty is a trial concept. It has nothing to do with stopping an ongoing crime. If a police officer is chasing someone, I would leave it to the officer – who has various forms of immunity from any liability that may or may not be available to you depending on your state law. #2 is correct, but I’d be more inclined to stick my shoulder in for a good rugby takedown.
Just because a suspect is being chased doesn’t mean they’ve committed a crime. Or that the law is even just. I’d hate to find out I caused somebody to be arrested for something as trivial as a gram of cannabis.
@philbegas : Please be sure to express those views if you are ever called for jury duty. You’ll be able to get back to your day job very quickly.
Or I could just wait until it comes down to the jury deliberation and use jury nullification 
Which is not a real thing and gets you a talking to from the judge and you will have committed juror misconduct by concealing your true opinion. Totally up to you.
Well you’re not supposed to say that you’re using it, you’re just supposed to repeatedly say you believe a person is not guilty. Also what is up with people starting stupid political arguments on CC lately.