6 Detective Riddles That Will Prevent You From Sleeping

A detective was locked in a room that had a dirty floor - with a shovel and an open window too high for him to climb out of. How did he escape?

A man was shot while sitting in a car, with no evidence of gunpowder residue or bullet holes found in the locked car. How was he killed?

A man killed his wife and carefully erased all the evidence - yet when he arrived at the crime scene upon the police's request, they arrested him. How did the detective know he killed his wife?

A woman shoots her husband, then holds him underwater for five minutes. A little while later, they both go out and enjoy a wonderful dinner together. How can this be?

A man went to a party and drank some of the fruit punch. He then left early. Everyone at the party who drank the fruit punch subsequently died of poisoning. Why did the man not die?

A man was found dead in a field of snow.
The only tracks left were a set of
footprints between two parallel lines. 
Who should the police be looking for?