An Onondaga County man who cut off his electronic monitoring bracelet, then raped a 10-year-old girl and killed her mother has pleaded guilty to murder and sex charges.

 29 year old David Renz admitted in county court this morning that he carjacked the two at a suburban Syracuse mall on March 14, stabbing the mother to death as she tried to prevent him from raping her daughter.

He had been under federal monitoring after a child pornography charge.

The 29-year-old Renz pleaded guilty to state charges of first-degree murder and sexual assault against a child. He is expected to be sentenced to life in prison without the possibility of parole, but the plea bargain can be withdrawn if the federal government seeks the death penalty.

47 year old Lori Bresnahan was stabbed to death that night after her car was hijacked by Renz in the parking lot of Great Northern Mall. Renz attacked Bresnahan in a secluded wooded area in the Town of Clay and also sexually assaulted a 10 year old girl with her that night. He was captured a short time ater the attack and he been in a federal holding facility since then.

It's believed that Renz tampered with his monitoring bracelet at least 46 times before the incident occurred and that tampering went unnoticed or ignored by federal probation officials. Since then, some employees of that office have been demoted or fired and there are calls for a change in proceedures.

Renz was wearing the bracelet since his arrest in January on child pornography charges.

David Renz will be sentenced on the charges November 1st.