Criminal and family court documents show 36-year-old Phillip Raymond Hernandez had served more than a year in prison after being convicted of corporal injury on a spouse, the Sacramento Bee ( http://bit.ly/YDovAX) reported Thursday.
Hernandez was arrested Tuesday after officers responding to 911 calls arrived at his Sacramento-area home and found his son Mathew dead from blunt-force trauma.
Police say Phillip Hernandez had gone into the backyard to get a hatchet and, for unknown reasons, broke through a sliding glass door to get back inside.
Officials say an elderly woman who lives in the home heard the glass shatter, ran into the living room and found Hernandez standing over his sleeping son with the axe, said Sacramento Police Officer Michele Gigante, a department spokeswoman.
The woman, who neighbors describe as the boy's great-grandmother, tried to stop the elder Hernandez, but he pushed her aside and attacked the fourth-grader with the hatchet, Gigante said.
Hernandez's 12-year-old son, the victim's older brother, was at home at the time of the attack, but wasn't harmed.
Hernandez is being held on the psychiatric floor of the Sacramento County Mail Jail. He declined media interviews Wednesday. He's scheduled to be arraigned Friday.
The boys' mother, Jessica Hernandez, lives out of state but was expected to arrive in the Sacramento area.
Sacramento police continue to search for answers in the horrific attack.
"So many questions of 'Why?' " Gigante said. "I can see how horrific the scene must have been by how the detectives are responding. As a parent, I couldn't even imagine it."
Records show the couple married in January 2001 and separated in April 2004. Not long after the separation, Phillip Hernandez was charged with corporal injury on a spouse and was sentenced to 120 days in jail and five years of probation.
Hernandez violated the terms of that probation in November 2005, when he was again charged and convicted of domestic violence and served prison time from July 2006 to October 2007, according to state records.
After his release from prison, the court imposed a custody arrangement in which the children would stay with their mother during the summer and their father the rest of the year, according to family court records.
Information from: The Sacramento Bee, http://www.sacbee.com