The 33-year-old father of three boys found stabbed in the back of an SUV has been booked on suspicion of murder in their deaths.

Luis Fuentes was booked Friday at the Los Angeles Police Department's Newtown station and being held in lieu of $3 million bail, Officer Mike Lopez said.

A furniture store owner found the bodies of Fuentes' three sons early Wednesday morning. Fuentes was in the front seat bleeding from stab wounds to his chest. A knife was found in the passenger seat.

The Los Angeles County Coroner's Office identified the children as 8-year-old Alexander Fuentes, 9-year-old Juan Fuentes and 10-year-old Luis Fuentes.

Investigators previously stated the boys' father was the only suspect in the case and that he would be arrested if he survived his injuries.

According to the Los Angeles Times (http://lat.ms/1OLr266 ), Fuentes' wife died in 2008 and he had suffered from depression ever since, despite the efforts of friends and family to help.

Armand Montiel, a spokesman for the LA County Department of Children and Families, said the agency was investigating any and all past contact workers may have had with the Fuentes family.

"By doing this, we seek to identify whether we provided the best services we could at the time the family was known to us," Montiel said Saturday.

Neighbors and relatives gathered at the home where the family recently lived Friday night to pray for the three boys. Several people recalled how the boys had seemed happy and loved playing soccer at a nearby park.

When Marisela Nuno heard from a neighbor that the family was struggling and living on the street, she said her husband spoke with Fuentes and offered a play to stay, but he declined and said they were staying with relatives.

"He was a very proud man," she told The Times. "He didn't want to ask for help."