Michael John Duggins Jr. was a lost teenager who turned to a heroin dealer as a sort of father figure, then got hooked on the drug, his attorney said Tuesday after a federal court hearing where the Roanoke County teen pleaded guilty to helping distribute thousands of bags of heroin.

Duggins, 19, was the third among 11 defendants to plead guilty to involvement in heroin trafficking in the Roanoke area. Authorities say the case, along with others, has raised alarms about heroin use among young people.

Duggins was in U.S. District Court in Roanoke to admit his role in what authorities describe as a drug network that imported heroin from Philadelphia, New Jersey and Maryland. "I sold heroin for Clifton Dwight Lee," Duggins told Judge Glen Conrad.

Duggins agreed that the government could provide evidence that he had obtained from Lee and resold at least 12,000 bags of heroin between April and July 2008. Assistant U.S. Attorney Don Wolthuis, who is prosecuting the alleged heroin network, said Duggins' cellphone had contained numbers for 27 customers, most of whom ranged in age from 17 into their early 20s.

Duggins, a graduate of Hidden Valley High School, pleaded guilty to conspiring to distribute more than 100 grams of a mixture containing heroin and cocaine.

After the hearing, Duggins' attorney Rena Berry said her client had been on his own, without parents or family, when he met Lee, who is now 32. Duggins became addicted to heroin and began selling it, she said.

Earlier, Conrad had asked Duggins if he had an address and Duggins replied that he did not, but could receive mail at his girlfriend's apartment. Wolthuis said investigators first heard of Duggins as a dealer operating in Southwest Roanoke County.

Wolthuis has described the heroin network as led by three men: Lee, a Roanoke resident who was known as "Lite" and who had roots in Philadelphia; Robert Dwayne "Dollar Rob" Early; and Alvin Macauley. All three have pleaded not guilty to a variety of federal charges linked to heroin distribution.

Investigators said that statements from multiple witnesses indicate that since 2002, the network brought between 130,000 and 250,000 bags of heroin into the Roanoke area. A bag contains about 0.03 grams of the drug, and a typical user may inject or snort one to 30 bags per day. Authorities have put the current street value of a bag of heroin at about $20 to $30, and said that Lee, Early, Macauley and their associates were able to obtain it in large quantities for about one-sixth the street price.

In court hearings last month, Safiyyah Amirah Omar and Eric Wayne "Cakes" Otey Jr., both 27, pleaded guilty to conspiring to distribute a mix of heroin and cocaine. Omar said she picked up heroin in New Jersey for Early. Otey was described as working with Lee to sell the drug.

At Otey's guilty plea hearing, authorities noted that they had investigated whether the web of heroin sales might be connected to a fatal overdose but could not prove it was linked.

One defendant among the 11, Cynthia Kay Anderson Nichols, faces two charges of contributing to a serious injury by supplying heroin to someone. She has pleaded not guilty.

On Tuesday, Conrad told Duggins that he faces a mandatory minimum sentence of five years in prison -- and a maximum of 40 years -- unless the government files a "substantial assistance" motion indicating that he aided the prosecution.

Duggins, who Wolthuis said made controlled heroin purchases from Lee after his own drug activity was discovered, said he understood.