Police arrested a 46-year-old man this week on charges that he kept a young teenage girl captive in a motor home parked in a remote orchard west of Moorpark.

Authorities said Shawn Barth held the 13-year-old girl captive for several months at least.

According to authorities, Barth came to Moorpark in May and parked his RV more than a mile from the nearest road so the victim would not escape. The landowner allowed Barth to stay on his property for a fee but wasn't aware of any wrongdoing, Detective Eric Buschow of the Ventura County Sheriff's Department said.

Investigators believe the crime started in San Bernardino County, where Barth first had contact with the girl. How she ended up living with Barth remains unclear.

The investigation, which began Sept. 11, unfolded as detectives followed Barth's trail from San Bernardino County to the Home Acres orchard near Moorpark, Buschow said.

The girl reportedly was allowed to go to school but didn't tell anyone about her ordeal. She was under the psychological and physical control of her captor, Buschow said.

Authorities were alerted by local school officials who suspected something might be wrong with the child's living situation. As middle school employees tried to obtain the girl's school records, they were told that there was a possible restraining order against Barth for a previous allegation of child molestation involving the same victim.

The district attorney filed four charges against Barth this week, including aggravated sexual assault. Barth is being held at the Ventura County jail with a $1million bond. His arraignment is set for Oct. 2 at 1:30 p.m.

Anyone with information about Barth should call the East County Sexual Assault Unit at (805) 494-8201.