While replacing one of my more difficult cache placements in a local park I noticed a City Cop slowly driving on the park entrance road. I walked through the woods to greet him and let him know what I was doing. "Oh they do that here too?" was the only cache related discussion. Apparently a driver had called in that there was a young man walking up the nearby main road with a rifle strapped over his shoulder and he was looking for this guy. That has been my only encounter with a LEO.
I have received logs for some of my caches that involved the seeker of the cache hearing what they thought were gunshots and then being told to move along by officers a short time later. Unfortunately for me these tend to be from caches that I placed very near to home but then I do live "up in the hood" now. Wasn't that way when I moved here but it seems to be now.