But the baby's family believes the boy died in his sleep, and not at the hands of his father.
Sasha Garcia, Sister-in-law: "He loved his baby because before the baby was born he was happy that he was going to have a baby."
Sasha Garcia says her brother in law Jose Santoyo was a good father who would never harm his baby.
Sasha Garcia: "He was the one always taking care of him when other people would hold his baby he was always watching to see if they did anything to him, you know see if were holding him right."
Sherrif's Detectives arrested Santoyo two weeks ago a day after he called emergency crews to report three month old Jimmy was unresponsive.
Chris Curtice, Fresno County Sheriff's Dept.: "I can't get into details of exactly what happened but suffice to say the father was responsible for the baby's death"
Santoyo's older brother defends him, calling 19-year old Jose Santoyo a responsible person who had a good job and had never gotten into trouble.
George Santoyo: "I know that there is a lot of people watching thinking that he did this because he's young and dumb and he did this because he got mad, but I'm telling you, my brother didn't do this, I know he wouldn't, he does have that kind of heart."
The baby was taken off life support last week Santoyo's family believes he may have died of SIDS or sudden infant death syndrome.
"Basically they stop breathing on their own and no one knows why. It says on the internet that it's no one's fault it just happens to a bunch of babies."
The boy's mother was at work when the baby was injured and also does not believe her husband could have intentionally hurt him.
Jose Santoyo was scheduled for a preliminary hearing today to face charges of injury to a child.
The hearing has been rescheduled to February 5th, when he will answer to murder charges.