(CNN)"Screech" is now a free man.
"Saved By The Bell" star Dustin Diamond spoke with former co-star Mario Lopez for "Extra" about what led up to his getting sentenced to four months in jail for stabbing a man during a Christmas Day 2014 altercation at a bar in Wisconsin.
Diamond said he and fiancée Amanda Schutz were out celebrating when a group of people started asking for photos.
"One of the girl's friends [Amanda] was talking to sucker-punched my fiancée," he said. "She leaned back to me and her face was covered in blood."
After one of the men in the group grabbed Schutz's hair, Diamond said, "I opened my pocket knife and said, 'Let my wife go immediately,' which worked."
Diamond denied that he actually stabbed anyone,saying that the victim "nicked his arm on the tip of" Diamond's pocket knife.
The actor served three months and said of his experience in jail, " It's pretty daunting, it's pretty scary going into that environment."
"I found that as long as you follow the rules and stay with the system, it works," he said. "You can get in and out unscathed."
Now that he is out, Diamond said he wants to focus on getting his acting career back on track and starting a family with Schutz.
"I want to put the tomfoolery and malarkey behind me... for that clean slate," he told Lopez. "Time for a change."