Prosecutors say a Pennsylvania teenager accused of killing his soccer standout girlfriend left investigators with a disturbing cache of evidence, including a bag packed with black knives.
Royce Moser, 18, has been charged in the fatal stabbing of Karoline Heintz, also 18, whose body was discovered in the back of her Jeep near the California Borough Library at about 12.30am on August 20, according to a criminal complaint reviewed by Our News Outlet.
The complaint alleges Moser pressured Heintz into going to his home before an argument erupted inside the vehicle, where he became enraged and stabbed her.
After the alleged stabbing, Royce is accused of calling his mother, Rachel Moser, and telling her what he had done. Neither has entered a plea.
Rachel, 56, was later charged after police said she helped her son dispose of Heintz’s body after he stabbed the teen in the chest and dragged her into the rear of the car, according to the complaint.
Prosecutors said Tuesday at a preliminary hearing that the mother and son initially did not speak with police about what happened, but later admitted their roles in the killing. It remains unclear how long Royce Moser and Heintz had been dating.
During the hearing, prosecutors called six witnesses and introduced 32 pieces of evidence, arguing the material shows the pair acted together to kill Heintz and attempt to dispose of her body.
That evidence included multiple images of black knives that appeared to be part of a kitchen set, according to photos obtained by Our News Outlet.
One of the knives was seen poking out of the top of a large black trash bag as smaller serrated weapons surrounded it.
Karoline Heintz, 18, was found stabbed to death in the trunk of her car on August 20 in California, Pennsylvania – a borough located in Washington County
Her boyfriend, Royce Moser, 18, has since been arrested and charged with allegedly killing her after he got upset during a conversation they had in a car. He has not yet entered a plea
Evidence photos showed black knives thrown in a large garbage bag after Heintz’s body was found
Another photo showed blood-soaked fabric or paper falling out of the same bag.
Still images of Blink home surveillance footage also captured the mother and son inside a home.
Rachel held what appeared to be a clothing item in her hand while Royce watched on with blue latex gloves on his hands.
Images of blood-stained blue latex gloves were also submitted into evidence.
Disturbing images of Heintz’s SUV depicted blood dripping from its trunk on the exterior of the vehicle.
Blood-stained clothing was found inside the trunk, the pictures showed. Dried blood was also found on the car’s door handles.
Another image appeared to show one of them driving a blue sedan with the same gloves on.
Police also snapped a picture of a washing machine with clothes in it. According to the criminal complaint, Rachel told her son to change his clothes, ‘take a bath and then a shower,’ and then placed his clothes in the machine.
The evidence also documented internet searches and phone history records from Royce’s phone.
Still images of Blink home surveillance footage also captured the mother and son inside a home. Royce wore blue latex gloves as his mom appeared to hold an article of clothing
Officers pulled a kitchen knife set from the bag during their investigation
Another photo showed blood-soaked fabric or paper falling out of the same bag
The knife set is seen amongst garbage in a bag outside
Around 11.10pm on August 19, just a little over an hour before Heintz was found, Royce searched ‘What removes fingerprints from objects,’ the documents revealed.
The teenager also looked up ‘How long does ring camera store video’ and ‘What foes [sic] god say about murder.’
He also searched ‘Can a 18 year [old] get the death penalty,’ the evidence, provided by the prosecution, stated.
Another search read: ‘What if a demon controled [sic] you [sic] and murder someone,’ the prosecution’s evidence read.
Police initially said that Rachel told them that her son had ‘demons, and that they told him to hurt the victim,’ according to investigators, the complaint said.
During their hearing, a judge upheld all of the charges filed against them.
Royce has been charged with one count of criminal homicide, two counts of tampering or fabricating physical evidence, two counts of abuse of a corpse, and obstructing the law and other government functions, court records stated.
His mother has been charged with tampering with evidence, abuse of a corpse and obstruction. On Tuesday, another count of criminal use of a communications device was tacked on. They have not entered a plea.
Blue latex gloves and white cotton swabs were found in a garbage can
Police also snapped a picture of a washing machine with clothes in it. According to the criminal complaint, Rachel told her son to change his clothes, ‘take a bath and then a shower,’ and then placed his clothes in the machine
Rachel Moser, Royce’s 56-year-old mother, had also been arrested and charged after police said she helped him dispose of his girlfriend’s body. She has not entered a plea
An image submitted to the court also showed blood dripping from the back of Heintz’s car
A blood-stained blue latex glove, that the pair appeared to wear in some images, was also found, according to evidence submitted to the court
Heintz’s heartbroken family released a statement through Pennsylvania State Police.
‘This is a parent’s worst nightmare. It has been devastating for family, friends, and the whole community,’ the family said. ‘Karoline was loved by all. She was a kind, smart, beautiful girl. We want justice for our “sweet” Karoline.’
‘Please respect our privacy as we grieve. Any questions refer to the PA State Police.’
Heintz was slated to play Division II soccer at PennWest University, and she also played hockey for her high school team.
She had planned to study biology, and after obtaining that degree, she would have attended LECOM medical school in Erie, Pennsylvania, according to her obituary.
She dreamed of becoming a physician one day, it read.
In a statement, the school said it ‘is deeply saddened by the tragic death of Karoline Heintz, who was a first-year student at the California campus.’
Our heartfelt condolences go out to her family, friends, and all those affected by this tragedy.’
![The evidence also documented unnerving internet searches and phone history records from Royce's phone. One of his searches read: 'Can a 18 year [old] get the death penalty.' It is unclear how long the pair dated](https://i.dailymail.com/1s/2026/09/03/10/111011611-16099765-The_evidence_also_documented_unnerving_internet_searches_and_pho-a-213_1788426201711.jpg)
The evidence also documented unnerving internet searches and phone history records from Royce’s phone. One of his searches read: ‘Can a 18 year [old] get the death penalty.’ It is unclear how long the pair dated
Heintz was slated to play Division II soccer at PennWest University, and she also played hockey for her high school team. She had planned to study biology
Her friends held a vigil in her memory, and her hockey teammates left their sticks outside their homes overnight in a tribute called ‘sticks out for Karoline.’
Friends of her family have gone on to set up an online fundraiser that allows people to send money or a meal to Heintz’s grieving loved ones.
Another donation page, made on GoFundMe, has gone on to raise more than $70,000 for her family.
Royce and Rachel are due back in court on October 13.
Our News Outlet has contacted lawyers for Royce and Rachel Moser for comment.
