A woman driven by a compulsion to harm children admitted in a Pittsburgh court that she murdered her best friend’s infant son in a plea agreement that is likely to keep her in prison for life.

Nicole Virzi, 32, had been charged with capital murder with the possibility of the death penalty before she opted to plead guilty Wednesday to third-degree murder and other charges.

She was sentenced to 35 to 80 years behind bars.

“Although this office was committed to pursuing this case to trial and its ultimate conclusion, after continued and on-going consultation with the family and considering the best interest of the community and its protection we agreed to offer the above plea and sentence,” the Allegheny County District Attorney’s Office said in a statement.

Virzi, a University of California San Diego doctoral student, was a close friend of the victim’s mother, Savannah Roberts.…