Jonathan Katan was sentenced Friday to life in prison without parole.
He was charged in February 2010 after Montgomery police officers responded to a call.
Katan told police he found his son wedged between the mattress of the bed and the bumper guard, but an autopsy showed the child died of multiple blunt force injuries to the head.
Ed Charmak was Katan's ex-father-in-law.
He told WSFA that Katan had threatened to kill himself if his daughter didn't allow him to see his children.
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