Top 5 things to do, to be a dumb criminal.

1. Ask Questions.
2. Leave Personal Info.
3. Know the person you steal from.
4. Stop in the middle of the crime.
5. Turn yourself in.

Ask Questions: If one is going to ask questions, they will obviously not be taken seriously. It doesn't even matter how good or bad the question is, you will look stupid.
Leave Personal Info: Credit cards, cell phones, business cards, it doesn't matter. Now a days, any of these will give all sorts of things away, especially if its not your credit card.
Know the Person you Steal from: "Hey, isn't this my computer?"...
Stop in the middle of a crime: What's the point of even trying? If one is going to stop they mind as well have not even gotten out of bed in the morning.
Turn yourself in: It's pretty self explanatory. You are telling the police that you just committed a crime and they should fine/arrest you.