Do I really have to confess this to you now? I took my car to the car wash to wipe away the evidence.
I see. What in the world did you do that for? What did you clean it with?
I used soap and water, but they don't know about it yet.
You are guilty then. You should not tamper with the evidence after committing a crime!
It's stupid for people to want my DNA. If I'm going to do something to someone I'm not dumb. I'm not going to leave a piece of evidence.
You have commited a crime, so you need to face the consequences. It will be better for you to confess, you will get a lighter sentence.