Updated

An upstate New York 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.

David Renz admitted in county court Wednesday 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 He is expected to be sentenced to life in prison without the possibility of parole, but the plea bargain can be withdrawn if the federal government seeks the death penalty.