A mistrial has been declared in the case of a Casper man accused of murdering his wife.

Judge Catherine Wilking declared a mistrial in the case against 46-year old Thomas Miller, a person on the stand, mentioned Miller had been involved in an affair.

During pretrial proceedings, that issue was deemed off-limits.

Miller's defense team then motioned for the mistrial.

Judge Wilking said that once the bell has been rung, it can't be un-rung and dismissed the jury.

Miller faces charges of first-degree murder, in the shooting death of his wife Natalie Miller, as well as charges of aggravated assault and two counts of child endangerment.

A new trial will be scheduled.

As of the time the mistrial was declared, Miller was still being held on $2,000,000 bail.