A federal judge declared a mistrial Tuesday in the case of a man accused of killing his neighbor's yellow Labrador after a courthouse therapy dog inadvertently entered the jury room during deliberations.

The incident occurred Friday when Clark, a black Labrador who serves as a therapy dog at the courthouse, broke free from his probation officer handler after the leash was dropped. The dog then wandered into the jury room where jurors petted him.

The defendant was facing charges related to the alleged killing of his neighbor's yellow lab, making the presence of a dog particularly problematic for the integrity of the proceedings.

Court officials determined that the contact between the therapy dog and jurors could have influenced their decision-making in a case specifically involving harm to a dog. The judge ruled that this contact compromised the fairness of the trial.

The case will need to be retried with a new jury. Court therapy dogs are typically used to provide emotional support to victims and witnesses, but are kept away from jury areas to prevent any potential influence on proceedings.