18-year-old accused of killing PennWest soccer player due in court today. Here's what to know.

Royce Moser, the 18-year-old accused of killing his girlfriend last month and leaving her body inside a vehicle near PennWest University's California campus, is due in court today for a preliminary hearing. 

Moser is accused of stabbing Karoline Heintz to death with a knife following an argument.  

Pennsylvania State Police troopers said that the two were having a conversation about the future of their relationship that likely went "a little bit south" and that Moser grabbed a "large" knife from the kitchen and stabbed Heintz in the chest. Moser told investigators that he had a "demon take over," telling him to stab his girlfriend, according to court paperwork. 

Moser's preliminary hearing is scheduled for this afternoon at the Washington County Courthouse. 

Royce's mother, Rachel Moser, has also been charged in connection with Heintz's death. Troopers said that she helped her son try to hide Heintz's body, which was discovered in the back of an SUV near the California Borough library. Her preliminary hearing is also scheduled for today. 

When the two were being led from the Pennsylvania State Police barracks following their arrest, the elder Moser uttered the phrase "I'm sorry," and when asked why she was sorry, she said, "that my son took a life."

In the wake of Heintz's death, there was an outpouring of support from the western Pennsylvania soccer community, as Karoline was an incoming freshman on the California Vulcans soccer team. 

Those who knew Karoline said they are choosing to remember her as an athlete with a "sweet, beautiful soul."