Dustin Diamond has started his prison sentence after being convicted over a bar fight
Diamond, 38, was sentenced to four months in prison for an altercation at a bar in Wisconsin, US. He was convicted of two misdemeanours: carrying a concealed weapon and disorderly conduct.
He was due to begin his sentence in June, but a judge put it on hold until he began his trial.
Diamond had told the jury he took out a pocketknife during the altercation to protect his girlfriend Amanda Schutz alone after she was punched in the face, and accidentally stabbed the man.
