A red herring diverts your attention from the issue at hand.
To perpetrate = do something illegal or wrong / to carry out a crime
A sidekick is a person closely associated with another as a subordinate
A clue is a piece of evidence that leads one toward the solution of a problem.
An alibi is an excuse for not being somewhere or doing something.
A motive is a reason for doing something.
To decipher is to find the meaning of something that is difficult to read or understand