Authorities in Pennsylvania have charged an 18-year-old man and his mother in the stabbing death of the teen’s girlfriend. Royce Moser of North Strabane Township faces a homicide charge in the death of Karoline Heintz, a student at PennWest California University. Heintz’s body was discovered on August 20 after she failed to return to the college. According to a police affidavit, Moser claimed he became angry with Heintz during a conversation in her vehicle in his driveway and that a "demon" told him to stab her. A preliminary hearing was held for Moser and his mother, Rachel Moser, in connection with Heintz’s death. An attorney for Royce Moser declined to comment on the charges, and a message left for a public defender representing Rachel Moser was not immediately returned. Police released a 37-minute bodycam video showing an officer discovering Heintz’s body in her Jeep. The officer reported finding an unconscious female with blood everywhere and called for emergency services. According to the affidavit, Moser told Heintz, "Wait, I have something for you," before retrieving a knife from his home. The victim fell out of her vehicle after being stabbed, and Moser placed her in the back hatch before getting into the driver’s seat. He then asked his mother to follow him to PennWest California University to drop off the vehicle. Heintz’s father had asked police to look for his daughter’s vehicle after she failed to return to campus. An AirTag in the vehicle showed she was in a parking lot, and police found Heintz’s body in the vehicle. The AirTag also indicated Heintz had been at Moser’s home earlier. Royce and Rachel Moser were later located at Rachel Moser’s residence in Beallsville. According to the affidavit, Rachel Moser told her son to bathe and change his clothes, which she placed in a washing machine. She then took the knife and put it in a garbage bag to dispose of in the trash outside her home. The knife was retrieved after investigators obtained a search warrant. Both Royce and Rachel Moser were charged with tampering with evidence, abuse of a corpse, and obstruction of justice. Rachel Moser, 56, was also charged with hindering the apprehension of a fugitive and criminal use of a communication device. Mother and son are being held without bail in the Washington County jail. Their next court appearance is a formal arraignment scheduled for October 13. Heintz’s family issued a statement asking the public to respect their wishes for privacy. "This is a parent’s worst nightmare," the statement said. "It has been devastating for family, friends, and the whole community. Karoline was loved by all. She was a kind, smart, beautiful girl. We want justice for our 'sweet' Karoline."