Police say a woman admitted that she stabbed her 7-month-old son to death in a popular Northern California park.

Chief Timothy Anderson of the East Bay Regional Parks District Police Department said Sunday in a statement that the 23-year-old mother from San Jose had a history of depression and appeared to have self-inflicted knife wounds on her wrist.

Police were called Saturday on reports of a damaged Honda sedan in the Del Valle Regional Park east of San Francisco. They found the car abandoned with the engine running and an empty child's seat.

Anderson says they were about to tow the car when the woman approached them holding her lifeless baby.

Investigators said they found a knife in the area.

The woman remains in jail on suspicion of murder.