LIVERMORE — A mother believed to be suffering from depression stabbed her 7-month-old son to death in a remote part of Camp Arroyo inside Del Valle Regional Park Saturday afternoon, authorities said.

The 24-year-old woman, whose identity has not been released but is believed to be from the San Jose area, was arrested on suspicion of murder, according to East Bay Regional Park District police Chief Timothy Anderson. She was set to be booked into Santa Rita Jail on Saturday night.

The incident began at 10:30 a.m. Saturday when East Bay Regional Park District police received a call about a collision at the dead-end of Arroyo Drive near Arroyo Camp, the site of a popular children’s camp inside the 4,400-acre park, located approximately 10 miles south of Livermore, Anderson said.

Responding officers found a gray Honda Civic with extensive front and rear end damage, but the driver was missing, according to Anderson.

Officers initially thought the car had been damaged by a hit-and-run driver, but after noticing a baby seat in the back, they decided to further search the area.

Around 12:30 p.m., a few remaining California Highway Patrol and East Bay Regional Park police officers saw a woman walking up Arroyo Road with a baby in her arms, Anderson said. The baby was not moving or making any noise. As the woman walked closer, officers saw that the child had been stabbed multiple times.

Police, as well as off-duty Livermore police Chief Mike Harris who was on a hike with his wife at the time, began performing first aid on the infant, but the child was declared dead at the scene.

It was not immediately known what may have spurred the woman’s actions, but she is believed to be suffering from some kind of depression, according to Anderson.

The woman also had a laceration or similar wound to lower part of her body. A pocket knife was found nearby and taken into evidence.

Arroyo Road was shut down for the remainder of Saturday to give investigators time to collect evidence. However, Anderson said the road is expected to reopen Sunday.

“This kind of thing rarely happens in our jurisdiction,” Anderson said as the brisk wind whistled through an eerily quiet section of Arroyo Road. “This is an extremely shocking case for us.”

In July 2009, the bodies of a Walnut Creek teenager and his mother were found at Mount Diablo State Park in an apparent murder-suicide.

In that case, Adam Williams, 16, a student at Las Lomas High School, was shot and killed by his mother, Judith Williams, at the Lookout Point picnic area, according to accounts by Contra Costa County Sheriff’s Office investigators, the coroner’s office and family.

The bodies of mother and son were found by park staff closing up that night. Sheriff’s Office detectives found a suicide note at Judith Williams’ Walnut Creek home.

Anderson said the next step of his department’s efforts Saturday night, in addition to collecting evidence from the park, would be to interview the woman to find out a possible motive behind the death of her son.

“I am very curious about why she may have done what she did,” Anderson said. “Many of our officers have families of their own. Something like this hits them really hard.”

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