The actor was initially thrilled when the judge took the potential jurors to one side and told them they would be part of a "murder one case" because he thought the trial would be good research for a future role.

But when the suspect walked into court and he smiled and pointed at Grace, the That 70s Show star started feeling he shouldn't be part of the decision making.

He explains, "This guy was totally guilty... You could tell this guy had murdered someone for sure.

"They (court officials) said, 'If any one of you 60 people... know anyone who's standing up, please raise your hand', because if you know one of the lawyers or if you know the defendant you can't be on the jury, and I didn't know the guy and so I didn't raise my hand, and as this incredibly guilty guy... sat down, he went like this (pointed at me). I didn't know what to do.

"I had to go up to the judge... and I was like, 'Hey, I think I saw the potential murderer recognise me... I'm kind of like a celebrity... I was on That 70s Show.

"I could see him (suspect), like, 'Cool, I'm gonna take the time in jail to really plan how I'm gonna rape and murder you once I get out'."