A federal grand jury indicted a darknet drug dealer  from Dallas, Texas, who is selling fentanyl to thousands of U.S. residents.

Fentanyl a dangerous synthetic opioid that is 50 times more potent than heroine and 100 times stronger than morphine. It is one of the major causes of overdose deaths in the United States, according to the Centers for Disease Control and Prevention (CDC).

On Thursday, the U.S. U.S. Attorney for the Northern District of Texas announced the indictment of Sean Shaughnessy, a darknet fentanyl dealer. A federal grand jury charged him with conspiracy to possess with intent to distribute controlled substances, distribution of a controlled substance, distribution of a controlled substance analogue and eight counts of money laundering.

The charges against Shaughnessy were the result of the first nationwide undercover operation called Operation Dark Gold. It is a coordinated operation targeting vendors of illegal goods on the darknet.

According to the indictment, Shaughnessy allegedly sold fentanyl and fentanyl analogues over the darknet. Internet users can only access the darknet and conduct transaction using specialized software. One user who allegedly bought fentanyl from him died of overdose.

Users allegedly use Bitcoin to buy Fentanyl from the darknet drug dealer

Shaughnessy’s buyers allegedly purchased the illicit drugs using cryptocurrencies such as Bitcoin. He then transferred his proceeds to other cryptocurrency wallets in exchange for regular fiat currency, which was sent to his home in Dallas. The darknet drug dealer wasn’t aware that he sent more than $120,000 Bitcoin to wallet addresses controlled by federal agents.

Special agents of the U.S. Immigration and Customs Enforcement’s Homeland Security Investigations (HSI) New York Field Office posed as money launderers on darknet market sites, according to the U.S. Department of Justice (DOJ).

The DOJ’s Money Laundering and Asset Recovery Section (MLARS) coordinated with federal prosecutors and law enforcement to investigate 65 targets. Their investigations already led to the arrest and impending prosecution of more than 30 darknet drug dealers.