LUBBOCK, Texas (AP) — A West Texas plastic surgeon has denied being involved in the 2012 slaying of a pathologist who was dating his former girlfriend.

Dr. Thomas Michael Dixon of Amarillo Dixon testified in court Wednesday in Lubbock, saying he never asked a business associate to harm Dr. Joseph Sonnier III. Dixon is accused of paying David Neal Shepard three bars of silver to kill Sonnier.

Dixon said he paid Shepard the silver, valued at $15,000 at the time, to take photographs of Sonnier with other women to prove that he wasn't committed to Dixon's former girlfriend. Dixon testified that he believed Shepard could do surveillance as a private investigator.

Shepard accepted a plea deal in the fatal stabbing and shooting of Sonnier and was sentenced to life in prison without parole. Dixon's original trial last year ended with a hung jury.