A Florida man was arrested on Saturday, after authorities say he killed a married couple while they slept and then had his stepdaughter help him bury the bodies in a swamp.

Officials with the Polk County Sheriff’s Office began receiving calls last week about a 19-year-old woman who was trying to sell a truck for $200. She told buyers the price was low because the owner no longer needed the vehicle.

It belonged to the victims, 33-year-old Raymond Cline 37-year-old Crystal Ann Cline, who were last seen Feb. 21.

Investigators went to the home of the 19-year-old woman, Amberlyn Nichols, after she tried to sell the couple’s truck. Sheriff Grady Judd says Nichols admitted that she and her boyfriend helped her stepfather hide the bodies in the backyard. She then led investigators to the decomposing bodies.

Todd Jackson is charged with two counts of first-degree murder. According to Nichols, he was angry because Raymond Cline owed him money. Authorities add that Jackson broke into the Clines’ home and shot them both in the head as they slept.

According to The Tampa Bay Times, Nichols and her boyfriend are facing charges that include failing to report a death and accessory after the fact.

She also told authorities that she had been living in the Clines’ home instead of the tent in a park where she typically sleeps.