A Missouri man who fatally stabbed another man because he mistakenly thought the victim was part of a sex-trafficking ring has been sentenced to life in prison.

The Springfield News-Leader reports that 39-year-old Christopher Manuel, of Republic, was sentenced Friday for the September, 2017 killing of Bill Dauzat.

He waived the right to a jury, and Judge Calvin Holden found him guilty in November of second-degree murder and armed criminal action after a bench trial.

According to court documents, Manuel stabbed Dauzat at least seven times in September 2017 outside of Dauzat’s Springfield home.

Manuel claimed that he was acting in self-defense, but Holden said there wasn’t enough evidence to support that argument.