In my experience trying to get information about the person in question only leads to further problems for you.

Given the erratic behavior of the person that allegedly verbally abused you, why didn't you, another passenger, or the flight crew immediately report the incident to the authorites as clearly in your judgement this was "unusual behavior", and I believe on the day of the purported incident we were on "orange alert". That's right, "ORANGE". Had you failed to do so and this person meant harm, it might be construed that you unknowingly abeted the person.

I would have exited the plane, waited until the individual was securely sealed in the aircraft, and then reported the incident to the police. There is certainly no reason for you to be subjected to a more unpleasant flying experience then it has become. It will also give the TSA, airlines, etc. a couple of things to think about. What is the person doing on the plane, and why did you exit the aircraft?

There are Ghandian forms of passive resistance that can be used by those who have a need to travel which creates a percieved need for their existence and pays the bills for those that resort to predatory practices in the name of security.