Mastermind

I murder a teacher. I put the bloody knife and my blue slinky bracelet into an envelope. I drop the envelope in the hall. I tell a girl about my crime, then go into a policeman’s office to turn myself in. I get there before the girl comes in to report me. The cop wants to go through my car and asks the girl if she’s seen it, but he shows her a large picture of a Toyota decked out in racing accessories. I’m surprised that they’re still letting me walk freely around the station. I start to think how I should have disposed of the evidence, but now I can’t go get the envelope.