I would try to video or photo him as much as possible. I usually have some cam equip w/ me.

I would also try to record as much info on vehicle and plate #, etc.

How about this? Meet him by vehicle and offer canned drink. See if you can get the empty (for recycling......). He might leave blood residue or atleast fingerprints on can. He may leave prints on something else too, if you are sharp you can " mark" these areas for gathering evidence later.

Physical evedence is great.

Uncle Matt (in IL)