Stand By Me
If you've got borderline brilliant observations like "A pile of shit has a thousand eyes!" We've got the costume for you.
You'll need a solid pair of black army boots so you can get to the body quickly, before the dead kid isn't dead anymore.
You'll need other army themed gear like dog tags, black thick rimmed glasses, a nylon bag with a canteen, an army green tee shirt and bed roll. An army supply store or thrift store is bound to have the
A pair of black jeans will complete you as Teddy. Then all you'll need to do is to defend your dad's reputation the way he defended the world from the Nazis.