It's the modern era copspeak for "suspect," when they want to get around constitutional requirements.

The interesting thing will be if he is indicted and goes to trial.

Could be a massive shit show, complete with jury dullards who agree with his political ideas, and therefore won't convict no matter what.

Would be quite the irony: supposedly, Trump could kill somebody in Manhattan, on video, and get away with it, when it is a leftist that actually has a shot of doing just that.