PHILADELPHIA -- A woman left her quadriplegic son, who has cerebral palsy, in the woods for several days and went to visit her boyfriend in Maryland, police said Saturday.

The 21-year-old son was found lying in the leaves covered with a blanket next to a wheelchair and a Bible near Cobbs Creek Park in southwest Philadelphia on Friday night.

Police described the son as severely disabled and said he was unable to communicate how he got there. They said their investigation indicates he was left there Monday, when his mother boarded a bus for Montgomery County, Maryland.

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CBS Philadelphia reported an arrest warrant has been issued for the woman, 41-year-old Nyia Parker, charging her with with aggravated assault, simple assault, reckless endangerment of another person, neglect of a care dependent person, unlawful restraint, kidnapping and false imprisonment.

The son was hospitalized with dehydration, malnutrition, a cut to his back and eye injuries, Lt. John Walker said.

"This kid's obviously a fighter," Walker said. "To see that kid laying there, it's heartbreaking to see that another human -- especially a mother -- could treat someone like that."

Walker said the son was exposed to the elements and other dangers.

"A lot of things could have happened out there," he said. "Obviously he's in the middle of a wooded area. You have wild animals there... this kid could not defend himself. He does not function at all."

The son's school became concerned about him and called an aunt. When the mother was contacted in Maryland, police said, she lied about his whereabouts.

"She indicated to both family members and police officers that the child was with her down... in Maryland," Walker said.

Authorities hope to have the mother back in Philadelphia Monday to face charges, according to CBS Philadelphia.

Walker said investigators will also examine "the longer term, which is how this kid was cared for, and what actions were taken and providing of services by different agencies."