Hells Angel member sentenced in federal court in Boston to 21 years

A federal judge in Boston has sentenced a member of the Hells Angels motorcycle gang with a long criminal record to 21 years in prison for possession of a firearm and ammunition after committing a felony, prosecutors said.

Eric Franco, 38, was the sergeant-at-arms for the Hells Angels chapter in Lynn, a statement from US Attorney Carmen Ortiz said. He was convicted of the charges in September and sentenced Tuesday in US District Court in Boston.

In May, Lynn police arrested Franco after finding the gun and ammunition in his apartment while investigating a report that Franco was assaulting his girlfriend, the statement said.

Franco’s criminal record already included three convictions for assault and battery with a dangerous weapon, and convictions for indecent assault and battery, failure to register as a sex offender, breaking and entering with intent to commit a felony, and conspiracy to violate the controlled substances act.

He was also convicted in Arkansas on an assault and battery in the second degree charge after he and five other Hells Angels stabbed four members of another gang, the prosecutors’ statement said.

Also today, the State Police announced that they had arrested four suspects and executed multiple search warrants on the North Shore as part of a probe into criminal activities of the Hells Angel and Red Devils motorcycle clubs.

Two of the four suspects arrested were Hells Angels; two others were Red Devils. Two other suspects are still being sought. All six face charges of kidnapping, mayhem, and extortion, State Police said.

The charges stem from acts committed against one male victim. State Police said no further details were being released about the victim or the crimes.

Todd Feathers can be reached at todd.feathers@globe.com. Follow him on Twitter at @ToddFeathers.