TAMPA, Fla. (AP) — A convicted sex offender was sentenced to life in prison Friday for strangling a 13-year-old girl and dumping her body in a pond.

Prosecutors had planned to seek the death penalty for David Lee Onstott, who was originally charged with first-degree murder in the death of Sarah Lunde, but backed off after a judge threw out his confession. No physical evidence linked him to the crime.

A jury convicted him Thursday of the lesser charge of second-degree murder.

On Friday, prosecutors and Lunde's mother asked Circuit Judge Ronald Ficarrotta to give him the maximum sentence for that charge, which was life.