A man accused of killing a 19-year-old University of Illinois-Chicago student in a campus parking garage allegedly strangled her to death because she ignored his catcalls, prosecutors said in court Tuesday.

Donald Thurman, a parolee facing first-degree murder charges in the case, did not know the sophomore honor student he is accused of killing but saw her for the first time Saturday evening.

According to prosecutors, UIC student Ruth George and a friend were returning from a semi-formal event with their professional fraternity. The pair took a Lyft to their campus and the friend went to her dorm room while George walked to her car.

George walked past the Chicago Transit Authority Blue Line UIC stop when 26-year-old Thurman noticed her, prosecutors said.

"[Thurman] thought she was pretty and tried talking to her, but [George] ignored him," a proffer from court read.

Thurman allegedly followed George into the parking garage and up to where her car was parked. Prosecutors alleged he was "angry that he was being ignored" so he "came up behind [George], grabbed her around the neck from behind, and put her in a choke hold."

That's when prosecutors say Thurman dragged her to the back seat of her car, face down and unconscious, before raping her and leaving a condom on the floorboard of the vehicle. Her body was found by her sisters and police the next day still face down in the back seat of her car.

Her sisters tried to perform CPR until paramedics arrived but George was pronounced dead at the scene. The Cook County Medical Examiner's Office later determined that George died as a result of strangulation, and ruled her death a homicide.

Thurman was seen on camera running from the parking garage wearing a "distinguishable white jacket," which authorities later found at his home, and his palm print was recovered off George's car, prosecutors said.

After his arrest, Thurman admitted to choking George and sexually assaulting her, authorities said.

Thurman was charged with first-degree murder and criminal sexual assault, UIC Chief of Police Kevin Booker said in a statement Monday. A judge ordered Thurman held without bail Tuesday.

Authorities said Thurman was previously convicted of armed robbery and sentenced to six years in prison, but only served two and was released from prison in December 2018. He was on parole at the time of the crime, officials said.

George was a member of UIC's Honors College and a "talented kinesiology student with dreams and aspirations to become a health professional and help others," UIC Chancellor Michael Amiridis said in a statement. "Our thoughts, our hearts and our condolences are with her family and friends during this trying period."

"She was the beloved baby of our family," George's family said in a statement. "We grieve with hope. We hold no hatred towards the perpetrator, but our hope is no other girl would be harmed in this way and for a mother to never experience this type of heartache."