NEW BEDFORD, Mass. (WPRI) — A man who prosecutors say has a lengthy criminal history was sentenced to at least a decade behind bars for trafficking fentanyl.

Kenny Gonzalez, 44, was arrested in September by New Bedford police, who were investigating him for running a “fentanyl delivery service,” according to the Bristol County District Attorney’s Office.

Prosecutors said police searched Gonzalez’s Nash Road apartment and found nearly 600 grams of the powerful painkiller in a lockbox and a safe inside the bedroom of his girlfriend’s two children. They also seized three phones, a drug ledger, and other items associated with dealing drugs.

At the time of his arrest, Gonzalez was about a year and a half removed from being released from prison in New York, having served time for first-degree manslaughter, according to the DA’s office.

“The defendant was found with a significant amount of fentanyl, a poisonous drug that is contributing to a significant amount of death and misery in our county,” District Attorney Thomas Quinn said III. “Given the volume of drugs he was selling as part of his fentanyl delivery service, he clearly is a danger and needs to be kept off the street.”