The best way to notice if someone is not good is by their actions, their behaviour. We do send off signals when we are not good because we act it out. “stinkin’ thinking, stinkin’ feeling, stinkin’ behaviour” We judge people for what they do, but we fail to look at “why are they saying that, why are they doing that?” If you stand back and really look at someone, you will see if that person is OK and you will see if they’re not. Don’t judge people for what they do, ask “Why are they doing that?” Us humans beings do not doing anything for no reason, otherwise we wouldn’t do it. Even in bad behaviour there is a payoff.
So look at your friend or family member and they will be telling you that something is not right. Take them aside and quietly talk to them about what you are seeing and that you are concerned. That you have seen them act in a way that concerns you. They then know that you have noticed them and you can see them.