PHILADELPHIA (AP) — An exterminator has been convicted of first-degree murder in the strangulation death of a Philadelphia pediatrician, a slaying authorities said happened after she questioned his work.

Thirty-seven-year-old Jason Smith of Levittown faces a mandatory life term without possibility of parole following the jury verdict Wednesday afternoon.

Prosecutors said he killed 35-year-old Dr. Melissa Ketunuti in her Center City home in January 2013, then tied her up with equestrian gear and set her body on fire. She had spent about five years at Children’s Hospital of Philadelphia as a physician and researcher.

Prosecutors said Smith was the last person known to have visited her home and confessed shortly after his arrest. Smith took the stand to say he confessed because he was exhausted by a police interrogation.

(© Copyright 2015 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)