Get this-one dude was convicted on a tiny, half pencil-eraser size piece from a dollar bill. He robbed, shot and killed his victim. One of the bullets went through victim's rt front pocket, and clipped off a tiny piece of the bill. A really good CSI tech (and no they do NOT interview suspects-they'd be fired for that!) picked the tiny piece of paper from the pocket, realizing its importance. When the suspect was apprehended, the bill was matched by stereomicroscope to the fragment....
I'm not smart enough to commit the perfect crime anyway, just fantasies really. A boy can dream, can't he!