This story was updated at 9:15 a.m. July 14 to include comments from Henry Koffie's attorney.

On Facebook, Henry Koffie called himself a "professional entrepreneur from SouthWest Philadelphia." He posted selfies flexing his muscles, looking pensive, and flashing large wads of cash.

On the darkest corners of the internet, Koffie allegedly branded himself as "Narcoboss" and used a Mexican booking photo of Joaquín "El Chapo" Guzmán as his profile picture.

In Philadelphia this week, federal prosecutors identified Koffie as a mail-order businessman, a "nationwide drug dealer" who shipped packages of the powerful narcotic fentanyl across the country using USPS Priority Mail.

According to charging documents, Koffie is responsible for the overdose deaths of two men in Portland, Ore., and has been linked to more overdoses in Florida, Idaho, Michigan, North Dakota, and Oregon.

Koffie allegedly ordered bulk quantities of fentanyl 14 times from China and Hong Kong. The drugs were shipped through  the U.S. Postal Service to his mother's home in suburban Philadelphia, prosecutors said, and Koffie picked up the drugs and repackaged them into smaller amounts, often pressing the powder into pill form.

He advertised on the dark web, a part of the internet where illegal activities are rife, taking orders from his diverse clientele over a notorious site called AlphaBay, which operated as an escrow service between buyers and vendors. (The site appeared Thursday to have been shut down by the federal government.)

Facebook

Then Koffie "prolifically" shipped out thousands of parcels using online postage services to buy postage, Priority Mail envelopes, and corner mailboxes, prosecutor's said. His most popular product was "2 Grams China White Synthetic Heroin Fentanyl Mix."

On internet forums, Koffie's alleged alter-ego, Narcoboss, earned glowing reviews for impeccable customer service. He was hailed as a reliable vendor who provided quick service and always included a little more product than the client had paid for. His reputation earned the attention of Homeland Security Investigations, the investigative arm of the Department of Homeland Security that pursues cross-border cybercrime.

"He was a top-10 target," said Brian Michael, the agency's deputy special agent in charge in Philadelphia. "He was a large importer of fentanyl." Using not much more than basic internet search tools, the agency determined that Narcoboss had filled more than 6,615 orders for fentanyl at $40 a gram. Federal agents estimated that during a one-year period, Koffie sold more than seven kilograms of the deadly drug and netted at least $260,000.

On June 10, Narcoboss became a short-lived internet star when he was mentioned in a New York Times story about opioid dealers embracing the dark web. Soon after, Narcoboss went silent. Customers, who had praised Narcoboss for two-day shipping, began to grouse about unfilled orders.

"Don't buy from this vendor," grumbled Reddit user Sanyardsent in mid-June. "He isn't shipping out orders anymore; we've been had."

"That's a damn shame," replied NoWayJesus1. "All the opiate vendors are either getting locked up or exiting."

Koffie, 32, was arrested July 5 at his home in Darby, just over the Philadelphia city line, and charged with multiple federal drug-trafficking counts. He was being detained at the Federal Detention Center pending transfer to Oregon, where he will face charges in connection with two fatal overdoses. When federal agents raided Koffie's property, they seized a half-kilogram of fentanyl, several pounds of a binding agent used in pill production, scales, and bank statements.

Michael, of Homeland Security Investigations, said he could not go into detail about the investigation.

"He's definitely one of the largest targets we've taken off the market in the Philadelphia area," Michael said.

Koffie's attorney said the feds may have the wrong man.

"I told the judge that for the purposes of the hearing, that my client was Henry Koffie, but not that he was Narcoboss," said Enrique A. Latoison, whose practice is based in Media.

"When you're dealing with a case on the dark net, anybody can be anybody," said Latoison."The U.S. Attorney is going to have to be able to prove that my client is Narcoboss, and that Narcoboss committed these crimes."

Asked about Koffie's most recent work history, Latoison would not go into specifics.

"I know what his other occupations are, but I can't comment," Latoison said. "He does have legitimate income."