A U.S. Coast Guard member keeps watch over a recent cocaine seizure in San Diego, Calif. (Mike Blake/Reuters)

A move to lower the lengthy prison sentence of a top associate of one of Washington’s most notorious drug lords has prompted a federal judge to ask whether the nation’s nascent drive to reduce prison populations might already be going too far.

U.S. District Judge Royce C. Lamberth expressed doubt last week about cutting two years off the 28 1/2 -year prison term of Melvin D. Butler, the Los Angeles-based broker for D.C. cocaine king Rayful Edmond III, whose trafficking network employed more than 150 people and imported as much as 1,700 pounds of Colombian cocaine a month into the city in the 1980s.

“It still gives me pause what Congress is doing,” said Lamberth, appointed by President Ronald Reagan in 1987 and who was chief judge of the district court from 2008 to 2013. “I would have thought the top drug kingpins in the country would not be the beneficiaries of what we’re trying to do here. Am I wrong?”

Lamberth’s comments come as members of Congress from both parties prepare to introduce legislation in September to cut federal prison crowding, even amid a surge of violent crime this summer that has lifted murder rates from historic lows in the nation’s capital and some other cities. The crime spike has prompted elected officials and police chiefs to calibrate their support for ending mass incarceration practices, saying repeat offenders are responsible for some of the recent violence.

Some conservative legal experts welcomed Lamberth’s doubts, warning that “the culture is losing its nerve” and turning excessively critical of police and discounting the role of harsh sentences in winning the fight against crime, as William G. Otis, a former federal prosecutor and special counsel for President George H.W. Bush, put it.

“If we cut back on the increased use of incarceration, we’re going to get more crime, and I think we’re already seeing that . . . right under our nose in D.C.,” said Otis, adjunct professor of law at Georgetown University. “If we go back and just walk away from what we undertook to reduce crime, we’re going to go back to where we were.”

Liberal law professors said that despite the charged rhetoric, a growing mass of empirical evidence — including the high financial and social cost of U.S. incarceration policies, falling crime rates and the experience of states and countries that use less harsh tactics — is forging a new consensus around appropriate punishments for nonviolent drug offenders.

“Twenty years ago, the idea of saying ‘Reduce sentences for kingpins’ would be unthinkable,” said Paul Butler, a former federal prosecutor and Georgetown law professor. “This in part shows how far we’ve come in terms of thinking more rationally, less emotionally about drug offenses.”

At issue in Melvin Butler’s specific case are guidelines approved in April 2014 by the U.S. Sentencing Commission that allow nearly 46,000 federal drug offenders now in prison to seek reduced sentences, subject to court approval.

About half of 100,000 incarcerated federal drug offenders are eligible for the changes, which came after the sentencing commission lessened punishments for most future drug offenders.

Nationwide, judges have granted requests in about 76 percent of 17,446 cases so far, including all 45 requests in the District, 196 of 200 requests in Maryland and 331 of 456 requests in the Eastern District of Virginia, which includes Northern Virginia and Hampton.

To be sure, these prisoners have no bearing on the current crime wavelet. None have yet been released, with the first set to go free Nov. 1.

The resentencing initiative also excludes career and armed career criminals, among others.

A 2014 sentencing commission study found that inmates set free in an earlier round of reductions aimed at crack cocaine offenders were no more likely to commit new offenses than those who served their full terms. Still, the recidivism rate for both was more than 40 percent.

The changes come as the Obama administration has prioritized further sentencing reform and clemency initiatives aimed at nonviolent drug criminals, and as Congress prepares to act.

Lanier: A ‘push to release’

Many Democrats and Republicans are searching for common ground on reserving prison for the most dangerous criminals and diverting the rest into other programs to reverse an eightfold increase in federal prison population since 1980 — from less than 25,000 to more than 214,000. U.S. prison costs have similarly grown sevenfold — from $970 million to nearly $7 billion — fueled largely by drug policies.

The question for Lamberth and policymakers is where to draw the line. That debate is sharpening as dozens of U.S. cities this year are reporting an uptick in violence.

The District has recorded 105 homicides so far this year, well above the modern low of 88 in all of 2012 but a fraction of totals a decade or two ago.

D.C. Police Chief Cathy L. Lanier and Montgomery County Police Chief J. Thomas Manger, also head of the Major Cities Chiefs Association, said last month that authorities nationwide must ensure that only truly nonviolent offenders are eligible for diversion programs, warning of gaps in how the criminal justice system identifies and tracks criminal histories.

“We are seeing far too many of our repeat violent offenders out here being reckless with firearms over and over again,” Lanier said. “There is a push to release a lot of people.”

While much of the consensus focuses on granting relief to low-level offenders, Butler lies near the other extreme. Of the first 17,000 eligible offenders who sought reductions, only 21 were in prison as long or longer.

Now 52, the onetime Los Angeles gang member landed in federal custody on April 28, 1989, as Washington was in the grip of a drug-fueled crime wave that would peak in 1991 with 479 homicides.

Edmond’s lieutenant

Butler was revealed to be a key partner to Edmond, a celebrity prince among the era’s shoot-’em-up drug gangs. At his arrest in 1989 at age 24, Edmond was reported to have introduced crack cocaine to the District, controlled 20 percent of the city’s cocaine trade and booked up to $1 million in profits a week. His network’s enforcers were linked to 30 killings.

After one prospective witness was shot and another’s residence was firebombed, he was convicted by the city’s first anonymous jury, who sat behind bulletproof glass in a courtroom cleared of spectators. Edmond was flown in daily to the 13-week trial by helicopter from the U.S. Marine Corps base in Quantico, Va.

Butler allegedly met Edmond in Las Vegas on April 6, 1987, after the championship boxing match between Sugar Ray Leonard and Marvin Hagler. He was convicted of linking Edmond to Los Angeles organizations with Colombian cocaine connections, resulting in the transport of kilos of cocaine to the District.

Butler was sentenced to life in prison, reduced to 34 years on appeal. With good time and other credits, he is projected to complete it in October 2017.

Lamberth called Butler “one of the two top ringleaders” for Edmond and recalled Edmond testifying that many of his lieutenants were armed.

“You’re saying that I can’t consider the fact that he was one of the biggest drug dealers in the history of our city?” the judge asked in an hour-long hearing Monday, where Butler’s attorney argued for his request, which was unopposed by federal prosecutors. “Congress has tied my hands and said I can’t consider that?”

Assistant Federal Public Defender Dani Jahn said Butler would face less time if he were sentenced under current law.

“I recognize this man’s stature and what happened in the ’80s,” Jahn said but added that he now had spent more than half his life in prison. “He’s not the person that he was. This is a very lengthy sentence.”

Butler will also remain subject to supervised release after he gets out, with “everything to lose by screwing up again,” Jahn said.

“That’s a very effective argument. I will think about it.” Lamberth said

Assistant U.S. Attorney Barry Wiegand said that the two-block open-air drug market at Morton and Orleans Place NE known as “the Strip,” where Edmond’s underlings once worked, no longer exists.

Offering no apology for past policies, he said Butler had served the great majority of his sentence and was eligible under federal sentencing changes that anticipated behavioral changes as young criminals turn into old men. He added: “What we did in the 1980s and 1990s was the right thing to do, and we did it well. Congress, without repudiating it, is taking things in a different direction.”

It is not clear when Lamberth will rule.