Gene Rossi is best known for his years as a federal attorney in the opioid investigation trials that led to 235 convictions, the most high-profile of which targeted doctors who overprescribed pain pills. (Diane Rossi)

After 27 years in the Justice Department, a Virginia prosecutor who targeted doctors who overprescribed pain pills is now hoping to tackle the state’s opioid crisis from a new angle: as lieutenant governor.

Gene Rossi aspires to join a Democratic administration trying to cope with the problem through a combination of harsh prosecution and holistic treatment. He left his job as a prosecutor in July and said he intends to make a formal announcement this month about his plan to seek office.

Rossi, 60, started his federal career in criminal tax enforcement and spent recent years training young assistant U.S. attorneys in Alexandria’s Eastern District federal court. He’s gone to trial more than 100 times. But he’s best known for Operation Cotton Candy, a multiyear opioid investigation that has led to 235 convictions.

Among the most prominent ensnared was William Hurwitz, a McLean pain doctor who saw three patients die of overdoses from his prescriptions. He was initially sentenced in 2005 to 25 years in prison, but his conviction was overturned, and after retrial, his term was cut in 2007 to less than five years.

“An increasing body of respectable medical literature and expertise supports those types of high-dosage, opioid medications,” Judge Leonie M. Brinkema said at the time.

She took the side of drug policy reform advocates who argued that prosecuting doctors makes it harder to help people who need relief.

“I think the aggressive prosecution can really undermine legitimate prescription to people who are in pain,” said Grant Smith, deputy director of national affairs at the Drug Policy Alliance. Law enforcement, he said, should not have “carte blanche permission to investigate and prosecute physicians and decide how much pain medication is too much pain medication.”

Rossi counters that the FBI and Justice Department used extraordinary discretion in targeting certain doctors.

“When a doctor runs a pill mill, he’s a drug dealer,” Rossi said. When Rossi tells doctors at Justice Department presentations how much Hurwitz was prescribing, he said, they have no sympathy, and they don’t fear for their own practices.

Likewise, Rossi has no qualms asking for long sentences for drug dealers he deems motivated by “pure, unadulterated greed.” In his last trial for the Justice Department in June, he helped persuade a jury to convict a woman of helping her husband sell opioids; she could go to prison for two decades.

But Rossi said his thinking has evolved on people who sell drugs to finance their own addiction.

“Twenty years ago, I didn’t blink an eye when someone was sentenced to 10 or 20 years,” he said. “Now I think: Is our society better off?”

He works on the Eastern District’s drug court, which offers an alternative to traditional probation for nonviolent offenders.

“I’ve watched Gene in particular come to understand . . . that these people aren’t moral degenerates, they don’t have weak backbones; they’re suffering from a disease,” said David Mercer, himself an alcoholic and a community representative on the court. Whenever someone graduated from the 18-month program, he said, Rossi insisted on bringing balloons.

Lawyers say Rossi is a respected prosecutor with a reputation for fairness. Originally from Connecticut, he lives in Alexandria with his wife, Diane. The couple have three children: a son in his teens and a son and daughter in their 20s. Rossi coaches youth basketball and is on the board of Friends of Guest House, a nonprofit that helps women who were incarcerated reenter society.

Rossi said that if elected, he would focus on sentencing reform and ways to help former prisoners succeed, in addition to seeking ways to combat drug addiction.

“It’s hard for me to imagine the U.S. attorney’s office without Gene there,” said Geremy Kamens, the lead public defender in the Eastern District. “He always fought hard, but what mattered most to him was that justice was done. If that meant an acquittal, Gene was fine with that.”

Defense attorneys and former prosecutors who trained under Rossi say he is particularly conscientious about turning in all available evidence to the opposition.

“He was very committed to being fair to those he was prosecuting. I wish that was an attribute shared across the DOJ,” said Justin Gelfand, who trained with Rossi before becoming a defense attorney.

Rossi said he is close to declaring his campaign for lieutenant governor. But he faces an uphill battle in the Democratic primary against Justin Fairfax, who came close to being the party’s 2013 nominee for attorney general, and potentially state Del. Eileen Filler-Corn (Fairfax). Relentlessly energetic and schooled in wooing juries, he for the first time is trying to win over a general public.

Rossi argues that his many years of public service — he actually trained Fairfax during the former federal prosecutor’s two years in the Eastern District — make a compelling case.