Inmates from the medium- and maximum-security blocks at the D.C. jail in 2014. (Jahi Chikwendiu/Washington Post)

POLICYMAKERS ACROSS the country have assailed mass incarceration, including by enacting measures intended to slash overlong prison sentences. That’s aimed at correcting real problems, including the risk that lengthy incarceration in harsh conditions often impedes rehabilitation. Unfortunately, recent steps by politicians in the District suggest that common sense may be losing out to enthusiasm for reform.

Two years ago, the District enacted a measure allowing inmates — specifically those serving lengthy prison terms for major violent crimes committed when they were 16 or 17 — to appeal for sentence reductions, provided they’d already served at least 20 years behind bars. That sensibly left judges with discretion to weigh the original crime’s severity against brain science showing that teenagers are impetuous and ill-equipped to weigh the consequences of their actions.

Then the D.C. Council went further. Again acting in the case of juvenile murderers and rapists, it removed a requirement that judges consider a crime’s circumstances when offenders ask for shorter sentences. The legislation, signed by Mayor Muriel E. Bowser (D), also allows convicts to file such requests after serving just 15 years behind bars, not 20, even if they are not yet eligible for parole.

Now the council, consisting of 11 Democrats and two independents, is poised to go further still. Under pending legislation, eligibility for sentence reductions would be expanded to include those who committed violent crimes up to age 25. The District’s top prosecutor, U.S. Attorney Jessie K. Liu, who opposes the measure, pointed out that its beneficiaries would include a kidnapper who participated in gang-raping a victim inside a stolen van; the murderer of a 7-year-old boy; and a killer who, having stuffed his victim’s corpse in a trash can, proceeded to execute the victim’s girlfriend for fear she could be a witness.

By stripping the law of the requirement that judges consider the original crime when weighing sentence reductions — and suggesting long sentences are rarely justified for youthful criminals “despite the brutality or coldblooded nature” of their offense — the council assured that proceedings will tilt in favor of convicts. The reform legislation’s sponsor, council member Charles Allen (D-Ward 6), contends the court could still consider a crime’s severity if it is weighed against other factors, including evidence of remorse and rehabilitation. However, he wrote to Ms. Liu earlier this year saying that prosecutors would contravene the intent of the law by raising the circumstances of a crime in opposing a sentence reduction. Judges at D.C. Superior Court would be justified in questioning whether they are allowed to consider the circumstances of the original crime when weighing an appeal for a reduced sentence.

The District has already gone further in the direction of sentence reductions than virtually any state; if the pending legislation is enacted, allowing sentence reductions for an expanded universe of youthful offenders who committed crimes between ages 18 and 25, that would be unprecedented. The effect would be to allow many of the city’s most violent offenders to seek release from prison in their 30s, regardless of their original sentences.

Out the window would go transparency and truth in sentencing — the assurance to victims and the community that punishment is what it appears to be. By discouraging judges from considering the original crime when they weigh reducing sentences, the council is putting the public at increased risk, unnecessarily.