So the Today show was covering the story of the Texas father who put the terminal beatdown on the guy molestering his daughter.
The bubbleheaded newsweasels there in New York were gravely intoning that now the man would have to face a grand jury! Was it justified, or was it murder? (I'll note that they couldn't seem to find a local to interview who did not allow as they'd have helped hold the perp down so the dad could get his licks in better...)
Meanwhile, they also provided a couple of key details that I had not yet heard: Apparently, the man was fetched by his son, who announced that his sister had been taken. And he set off to find her and came across her half-naked and screaming and the baby raper with his trousers around his ankles...
Now, normally I'm a big proponent of "You are not a Caped Avenger. When you stumble across some random random street scene you interpret as a crime in progress, the best thing to do is dial 911 and, at most, yell 'Hey! I just called the cops!' and hope whichever one is the actual bad guy runs off."
Even a seemingly clear-cut scenario like "the man in the grocery store parking lot wrestling with the woman in front of the screaming kid" may actually be the custodial parent trying to keep his psycho ex- from kidnapping their child, or an off-duty cop getting assaulted by a woman whose babydaddy he just put away for armed robbery. Unless you have all the information, it's not a good idea to rush to judgement.
However, I'm trying to think of an alternate scenario where you could stumble across a screaming toddler being sexually assaulted by a grown man with his trousers at half-mast and not be cleared guns hot. I mean, what could he say that makes this okay and would prevent you from being green-lighted weapons free? "It's alright, I'm her dad?" or "I know what this looks like, but he's really consenting?"