LOS ANGELES (CBSLA.com) — Police on Wednesday said they want to question the biological father of a young boy found dead in an Echo Park home.

On Monday afternoon, police got a 911 call from Jose Pinzon who said that his wife told him that his stepson was dead.  When investigators arrived at their home on Santa Ynez  Street, they found  the 11-year-old wrapped in a blanket in the closet. Police said the boy looked like he had been suffering from malnutrition and physical abuse and had been dead for a few hours.

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“It’s one of the worst cases I’ve seen in my career,” LAPD Detective Moses Castillo said.

Castillo and his team at LAPD’s Abused Child Unit arrested the boy’s mother Veronica Aguilar, 39, for child endangerment resulting in death.  Aguilar is expected in court and the boy’s autopsy will be performed Wednesday.

Police also say the Los Angeles Department of Children and Family Services received reports of possible abuse or neglect at least three times between 2009 and 2012 involving the boy, but no case was filed.

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Detectives say the boy had not attended classes in the L.A. Unified School District and are looking into whether the child has spent time in Mexico where they believe the boy’s father may be.

Police say the father could offer key information in the case.

“I think it’s a big piece of the puzzle so that we could find out more about this child,” Castillo said.  “Find out about his well-being and what led up to the mom having sole possession of this child.”

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Investigators said they will canvass the neighborhood as well as other locations the family has recently lived to piece together the events that led up to the boy’s death.