A Pennsylvania teenager fatally stabbed his girlfriend, a college soccer player, then enlisted his mother’s help to clean up the crime scene and move the victim’s body, police said Thursday.

Karoline Heintz, a freshman defender at Division II PennWest California, was found dead in the back of a Jeep Cherokee at about 12:24 a.m. Thursday near the California Public Library, roughly 35 miles south of downtown Pittsburgh, officials said.

Even before she was found, law enforcement had been doing a welfare check on the freshman because family members called in to report that “she never made it to that university,” Pennsylvania State Police Trooper Rocco Gagliardi told reporters.

Investigators believe that hours earlier Heintz had “met with her boyfriend, Royce Moser, outside his father’s residence in North Strabane to talk,” according to a statement from Pennsylvania State Police.

Moser, 18, got angry, went inside the house, grabbed a large kitchen knife and stabbed Heintz to death in the chest, according to police.

“We believe it (the murder) was originally the result of a domestic situation,” Washington County District Attorney Jason Walsh told reporters.

The suspect then put her body in the Jeep’s rear hatch and drove to his mother’s residence in Beallsville, police said.

There, Rachel Moser wiped down the Jeep with cleaning sprays and gave her son latex gloves, instructing him to follow her to the university, according to police. The two then “left the Jeep Cherokee near the California Public Library with Karoline Heintz still inside,” police said.

Rachel Moser drove her son back to her home, where he cleaned his clothes and showered, police said.

Royce Moser has been charged with homicide, tampering with evidence, abuse of a corpse, conspiracy to commit tampering with evidence, conspiracy to commit abuse of a corpse, and obstruction of justice.

Rachel Moser has been charged with hindering the apprehension of a fugitive, tampering with evidence, abuse of a corpse, conspiracy to commit tampering with evidence, conspiracy to commit abuse of a corpse and obstruction of justice.

As of Friday morning, it was not clear whether either had retained or been assigned a defense attorneys to speak publicly on their behalf.

“PennWest University is heartbroken by the tragic death of Karoline Heintz, a first-year student-athlete at the California campus,” the school said in a statement on Friday.

“Our deepest condolences are with Karoline’s family, friends, teammates, and all those whose lives she touched. We are focused on supporting members of our university community as they grieve this devastating loss.”