Published: Apr 02, 2010 5:08 PM EDT

PENSACOLA, Fla. - The 14-year-old Florida Panhandle boy

charged in his father's murder said he was "sick of his life and

wanted to leave or do something."

 

That's according to an affidavit which reveals new details about

the March shooting.

 

According to the document, William Williams and his son were

watching "Survivor" on television when the teen excused himself

and retrieved a gun from his father's bedroom.

 

The teen told investigators he aimed the weapon at his father

and pulled the trigger. It didn't fire. The teen allegedly then

fired again, shooting Williams in the chest.

 

The boy said he later went to his room to get his Christmas

money, planning to run away.

 

He has pleaded not guilty to the charges.