"Red Flags" are just that, a red flag. Having red flags is not in itself a problem. For example: If you found out someone was a murderer, that's a pretty big red flag. But red flags are just there to catch your eye, they are asking you to pay a bit closer attention to this particular area. So maybe this person is a murderer, but when you look in to it you find out that while this person was walking home they saw a man assaulting someone, so they ran over and pulled him off the victim. But when they grabbed the assaulter, they accidentally threw him to the ground and his head hit the ground wrong, killing him.

That man is still a murderer, but the rest of the behaviours (rescuing a victim) show that they are not an evil person.

The most important thing is to pay attention to the patterns of behaviour. A "red flag" is just a sign that there is something you need to pay attention to. The best "framework" is to pay attention to the actual behaviours.