NEWARK - Federal authorities say that they've arrested the reputed leader of one of the New Jersey's most violent street gangs, the Grape Street Crips.

The U.S. attorney's office announced Thursday the arrests of 39-year-old Corey Hamlet, of Belleville, and three other men on charges including racketeering, extortion, robbery and drug trafficking.

Authorities say they've linked Hamlet to several murders and attempted murders as part of a racketeering conspiracy.

U.S. Attorney Paul Fishman says the investigation started about nine months ago when more than 70 alleged Grape Street Crips gang members were arrested.

The U.S. attorney's office alleges Hamlet ordered the killings of people believed to have cooperated with law enforcement or been disloyal to the gang.

Fishman says it’s alleged that the Grape Street Crips Gang controlled much of the heroin trade in North Jersey. Hamlet allegedly continued to run the operation even while serving a 69-month sentence in federal prison. He was released in 2012.

Hamlet and his alleged associates appeared in Newark Federal Court Thursday afternoon.

The Associated Press wire services contributed to this report.