I'm sure that any "articulable reason" which would justify a Terry Stop would be admissible in a court of law and thus would constitute "evidence".
What "reasonable suspicion" would allow you to detain Grisham for poaching?
I’m sure that any number of reasons could be strung together... walking down a road ... known rabbit and or small game area ... Rifle known to be a small game caliber (.223) ... Carrying a bag to potentially hold illegal game (backpack)
My point is that if anyone of us can come up with these “reasonable suspicions”, LEO’s can as well. A sad state of affairs and one that will only be corrected if we put in place legislators who have and present a strong defense of the 2nd Amendment. That will only happen if gun owners get involved in the election process.