Defendants are accused of three killings since 2008.
The updated indictment was unsealed Thursday in White Plains. It adds 15 new defendants for a total of 31. U.S. attorney Preet Bharara (bah-RAH'-rah) says 14 have been arrested and one is a fugitive.
Besides murder, the defendants face various charges of racketeering, attempted murder, robbery and assault. All 31 are charged with a drug distribution conspiracy.
Bharara says the original charges filed in May against gang members had helped clean up Newburgh, located on the Hudson River about 60 miles north of New York City. He says the new charges show the crackdown is continuing.