I had a Kel-Tec 3AT, which is just like a Ruger LCP in my pocket for years, and handed it to my friend to deliver the coup de grace to a buck antelope.
It did not fire. There was too much pocket lint inside. I took out the magazine, pulled back the slide, and blew out a huge ball of lint. Then he killed the antelope with it.
I now check firearms for pocket lint, especially the P3AT and LCP.