When I found it in my car,I thought to myself,"Did this car belong to some murderer?" I went to go wash my car,you know the usual.I was done cleaning my car from the outside, then got the vacuum and started cleaning the interior.I was cleaning the back seats and under them.After that, I vacuumed under the front seats.Cleaned the driver's,then when I was vacuuming under the passenger's seat, when something sharp poked my hand.I looked under and found this big ass rusty knife.It is 15 inches long in total.The blade is 10 inches long.What should I do with it?keep it or be a good boy and give it to my parents?