It has nothing to do with predictive policing. I don't understand this example, it has nothing to do with detecting intent. You're looking for evidence of a past misdeed.
False positive and false negative rates are non-zero, as with almost anything, but the tools are pretty good. I encourage you to give them a try. Pangram is a good state-of-the-art choice and you can try it for free. They also publish evals and other data about their approach.
> but the tools are pretty good. I encourage you to give them a try.
I have given them a try and can confirm the exact opposite. Plenty of others have given them tries and have confirmed the exact opposite.
Regardless, the “better for a hundred guilty men to go free than for one innocent man to hang” principle applies here.