An 18-year-old college soccer player was allegedly stabbed to death by her boyfriend shortly before beginning her freshman year at Pennsylvania Western University, and police say the suspect’s mother later helped him try to cover up the killing.

Karoline Heintz, an incoming freshman and member of the PennWest California women’s soccer team, was found dead inside her Jeep Cherokee near the university’s California campus.

Her boyfriend, 18-year-old Royce Moser, has been charged with homicide and several other offenses. His mother, Rachel Moser, also faces multiple charges for allegedly helping her son conceal evidence after Heintz’s death.

According to court documents, Heintz met Royce outside his father’s residence in North Strabane, Pennsylvania, to talk while sitting in her vehicle. Royce allegedly told investigators he became angry over something Heintz said, though he claimed he could not remember what sparked his anger.

He then allegedly told investigators a “demon” took over and instructed him to stab Heintz.

“He then had a ‘demon take over’ him and tell him to stab Karoline,” court documents state.

Police say Royce went inside the residence, retrieved a knife and returned to the vehicle, where he allegedly stabbed Heintz in the chest. He then placed her body in the rear cargo area of the Jeep and drove away, according to the criminal complaint.

Royce allegedly called his mother following the attack. Investigators say Rachel told him to bring the vehicle to her home and pull it into the garage.

There, Rachel allegedly gave her son latex gloves and helped clean the vehicle with disinfectant spray. The two then drove toward PennWest’s California campus, where Heintz’s Jeep was left in a parking lot near the California Library, according to court documents.

Rachel is also accused of placing the knife allegedly used in the killing in a garbage bag and putting her son’s clothing in a washing machine.

The California Police Department was contacted shortly after midnight Thursday when Heintz failed to return to campus. Officers searching near the library discovered her body in the rear hatch of the Jeep.

Royce faces charges including homicide, tampering with evidence, abuse of a corpse, conspiracy and obstruction of justice. Rachel faces charges including hindering apprehension, tampering with evidence, abuse of a corpse, conspiracy and obstruction of justice.

PennWest University mourned Heintz as a first-year student-athlete whose life was cut short just as she was beginning college.

“PennWest University is heartbroken by the tragic death of Karoline Heintz, a first-year student-athlete at the California campus,” the university said. “Our deepest condolences are with Karoline’s family, friends, teammates, and all those whose lives she touched.”

The university said it is supporting members of the campus community as they grieve the devastating loss.