A Cape Cod man connected to the seizure of more than two pounds of the illegal drug methylone in East Wareham was sentenced on Monday in U.S. District Court in connection with running a large-scale marijuana operation.

David Landry, 29, of Mashpee, was sentenced by Judge Indira Talwani to 78 months in prison and three years of supervised release. Landry is currently serving a four-year state sentence for heroin distribution.

In Dec. 2015, Landry, his mother, Diane Johnson, Justin Groom and Evan Lopes, were indicted with possession with intent to distribute marijuana, conspiracy to manufacture marijuana, money laundering, possession with intent to distribute methylone (also known as “molly”), being a felon in possession of a firearm and money laundering conspiracy.

From May 2014 to January 2015, Landry and Groom conspired to manufacture and distribute marijuana, and possessed marijuana with the intent to distribute it. Landry, who was arrested and has been in state custody since Sept. 12, 2014, continued participating in the criminal offense while in jail on the state charges, according to state officials. On Jan. 6, 2015, law enforcement authorities executed a search warrant at a residence on Cheryl Lane in Pocasset, and seized marijuana plants and growing equipment. Groom is alleged to have used the proceeds of the illegal activities to pay the rent on the Cheryl Lane house.

It is alleged that Lopes, aided by Landry, possessed with intent to distribute methylone, a Schedule I controlled substance similar to MDMA. On Jan. 15, 2015, law enforcement authorities executed a search warrant at a residence on Point Pleasant Circle in East Wareham and seized two kilograms of methylone and several letters Landry sent to Lopes while Landry was in jail.

Officials said Landry had a loaded .40 caliber semi-automatic pistol on Jan. 21, 2015, when law enforcement officers recovered the pistol during a search of a residence on Acapesket Road in Falmouth. Landry pleaded guilty to possessing the gun and directing an associate to its location. Finally, from 2010 to 2015, it is alleged that Landry and his mother, Diane Johnson, conspired to launder drug proceeds in order to disguise the nature of the funds and promote continued drug trafficking.

During the sentencing hearing, the government argued that Landry is a dangerous offender whose criminal conduct lasted from at least 2010 to 2015, and continued while he was in state custody. The marijuana grow operation involved sophisticatedequipment for which Landry paid over $40,000, and from which Landry expected to produce substantial illegal revenue for years. The money laundering involved multiple bank accounts and hundreds of thousands of dollars.

On March 2, Groom was sentenced to two years of probation after pleading guilty to marijuana and money laundering offenses. Lopes and Johnson are awaiting trial.

The defendants are presumed to be innocent unless and until proven guilty beyond a reasonable doubt in the court of law.