A federal grand jury returned an indictment charging four men for marijuana and oxycodone trafficking.

Attorney William J. Ihlenfeld announced on Monday, March 9, that Chad Allen Workman, 37, of Beverly, Charles Shawn Shannon, 54, of Belington, Roy Melvin Isner, 62, and Mark W. Lambert, 39, both of Elkins are alleged to have been a part of a drug operations.

The defendants were each charged with one count of marijuana conspiracy, and face up to five years in prison and a fine of up to $250,000.

Workman faces additional charges that include, one count of money laundering, one count of maintaining a drug involved premise, one count possession with intent to distribute marijuana, one count of possession with possession of an unregistered machine gun, and one count of possession of a firearm by an unlawful drug user. If Workman is found guilty of all of these charges, he faces up to 60 years in prison combined, and also would have fines that total up to $1.75 million combined.

Lambert is further charged with one count of maintaining a drug involved premise, and four counts of distribution of marijuana. Lambert faces up to 25 years in prison on combined charges and up to $750,000 in fines.

Isner’s additional charges include, one count of maintaining a drug involved premise, one count of possession with intent to distribute marijuana, and one count of possession with intent to deliver oxycodone. Isner faces up to 45 years in prison on the combined charges and up to $1.75 million in fines combined.

Shannon is further charged with two counts of distribution of marijuana, faces up to five years in prison and up to $500,000 in fines.

Ihlenfeld said the defendants are alleged to have worked closely with other individuals previously charged with drug trafficking in the Northern District of West Virginia. In December 2014, four individuals were charged for their roles in a scheme to procure oxycodone from sources in other states. In another related matter, a Florida man pleaded guilty in February 2015 to drug distribution charges.

Assistant U.S. Attorney Stephen Warner is prosecuting the case on behalf of the government.