Michael De Santa

"Why did I move here? guess it was the weather..."

- The protagonist during the teaser tralier

 is the currently unnamed protagonist of Grand Theft Auto V.

Background
Judging by what he says in the trailer he was once a criminal. He left that line of work and moved to Los Santos, presumably he was wealthy as he mentioned buying a big house, to live a normal life with his family. He mentions having children whom he wants to be like the children on TV.

For a currently unknown reason he decided to return to a life of crime, at some point robbing a bank with two unknown accomplices.