Katelyn Beard’s body was found in a rural area north of Jackson, shortly after police found some of her clothes.
Jackson Police Department spokeswoman Colendula Green said Dewayne Thompson, 19, was captured Monday and initially charged with aggravated assault, kidnapping and auto theft. She said the aggravated assault charge would be upgraded.
Jackson’s interim police chief, Lee Vance, said Thompson helped in the search for Beard.
“The motive is unclear,” Vance said in a video posted to The Clarion-Ledger website. “The only thing he’s indicated, that they were consuming drugs together. But more specifically why he committed this murder – he hasn’t told us that.”
Hinds County Coroner Sharon Grisham-Stewart said Beard’s body was left near a road and was not buried.
Mississippi Highway Patrol issued an Amber Alert on Sunday night for Beard.
Jackson police found her car, with a Greene County license plate, Monday morning in west Jackson, less than a mile from where she was taken. Thompson was arrested hours later after he was found in a vacant home nearby.
It was not immediately clear whether Thompson has an attorney.