In Terminator, Kyle Reese is arrested by the police and promptly treated as a raging psycho by telling them about time traveling Rondos robots.
He was sent by John Connor, who - as we are given to know via backstories from T1 and especially T2 - had quite a lot of (mostly successful) experience of dealing with the cops from the somewhat-wrong-side-of-the-law.
Why didn't Connor bother giving Reese - as part of his mission briefing - the idea that he might run afoul of the police, and how to best handle the situation in the least damaging way?