Adam Belmont was charged Monday with killing 25-year-old Alyssa Van Meter.
DuPage County Prosecutors say Belmont on Saturday around 9 p.m. allegedly broke into the Forest Drive apartment that he had shared with Van Meter until they broke up earlier this month. Police say Belmont confronted Van Meter and after a brief verbal confrontation, a physical altercation between the two ensued.
Police say Belmont stabbed her to death in her bedroom with a knife that bore their names and anniversary date.
Belmont faces charges of first-degree murder, home invasion and aggravated sexual assault.
Prosecutors say that Belmont allegedly told police he entered the apartment by climbing onto a balcony and cutting a screen. They say he first choked Van Meter unconscious, then allegedly stabbed her in the heart once as she began to regain consciousness. Police say he then sexually assaulted her.
The victim was found on the bedroom floor.
"The allegations against Mr. Belmont are very disturbing in that he allegedly took the life of his former girlfriend because she began dating someone new and was moving on with her life," said DuPage County State's Attorney Robert B. Berlin.
The Associated Press contributed to this report.