The owner of two Boston-area pizza shops has been sentenced to more than eight years in prison for subjecting employees to years of violence and intimidation, according to prosecutors.

Stavros Papantoniadis was sentenced in federal court to 102 months in prison on Friday, along with one year of supervised release and a $35,000 fine, according to a news release from the US Attorney’s Office for the District of Massachusetts.

Papantoniadis coerced or attempted to force six victims — five men and one woman — into working under harsh conditions at his Stash’s Pizza locations, prosecutors said, as well as employing violent tactics and threats of deportation to ensure compliance with demands.

In June, he was convicted on three counts of forced labor and three counts of attempted forced labor.

CNN has reached out to Papantoniadis’ attorney for comment.

“Labor trafficking exploits the vulnerable through fear and intimidation, all in pursuit of the almighty buck,” said Acting US Attorney Joshua Levy in the news release. “That is what Stavros Papantoniadis did when he violated the rights of the people working in his restaurants.”

Papantoniadis intentionally employed undocumented workers for back-end roles and manipulated their immigration status, Levy said.

Authorities discovered that Papantoniadis operated his pizza shops with a skeletal staff, forced workers to perform grueling shifts of 14 hours or more, often seven days a week. He closely monitored them with surveillance cameras, according to prosecutors.

Papantoniadis violently choked a worker who expressed his intention to quit, causing the victim to flee in fear, investigators found. When a different employee attempted to leave, Papantoniadis chased him down Route 1 in Norwood, Massachusetts, and falsely reported him to the police in a bid to intimidate him into returning to work.

Papantoniadis “exploited and abused his employees, denying them the basic dignity every person deserves,” Michael J. Krol, a Homeland Security Investigations special agent in charge, said in the release. “Today’s significant sentence sends a message to employers — employees deserve to work in safety, free from harassment and abuse.”