[JURIST] The US Supreme Court [official website; JURIST news archive] on Monday decided [opinion, PDF] 6-3 in Barber v. Thomas [Cornell LII backgrounder; JURIST report] to uphold the method used by the federal Bureau of Prisons (BOP) [official website] for calculating "good time" sentence reductions for federal prisoners. The Sentencing Reform Act [18 USC § 3624(b) text] permits federal prison authorities to award prisoners credit against prison time as a reward for good behavior. The court upheld the BOP's interpretation of the act's use of "term of imprisonment" to mean time served, rather than sentence imposed, as it is interpreted throughout federal sentencing statutes. Therefore, a prisoner's good time credits for a year are not earned until a prisoner has served that year and has shown compliance with institutional rules. Justice Stephen Breyer, delivering the opinion of the court, held that the Bureau's method reflects the most natural reading of the statute and therefore passes muster:

The statute's language and purpose, taken together, support the BOP's method. That method tracks § 3624(b)'s language by providing a prisoner a maximum credit of 54 days for each full year of imprisonment and a proportionally adjusted amount of credit for any additional time served that is less than a full year. The BOP's method also furthers the basic purpose of the statute…[which is] the sentence the judge imposed would be the one the offender actually served, with a sole statutory exception for good time credits. Section 3624(b) states the reason for the exception: to provide an incentive for prisoners to "compl[y] with institutional disciplinary regulations." The exception is limited and tailored to its purpose – credit is earned at the end of the year after compliance with institutional rules is demonstrated and thereby rewards and reinforces a readily identifiable period of good behavior. The BOP's approach furthers § 3624's objectives by tying the award directly to good behavior during the preceding year.

Breyer concluded that since BOPs method reflects the good credits provision's most natural reading and is consistent with its purpose, the court should not determine the "extent to which Congress has granted the BOP authority to interpret the statute more broadly, or differently than it has done here." Justice Anthony Kennedy dissented, joined by Justices John Paul Stevens and Ruth Bader Ginsburg.

The ruling stemmed from two Ninth Circuit cases that were consolidated under the Supreme Court's grant of certiorari [JURIST report]. Petitioners Michael Barber and Tahir Jihad-Black are serving sentences in federal prison for various gun and drug charges. Under the petitioners' proposed method of awarding credit for "time imposed," federal prisoners would receive good time credits for years they do not end up serving. The petitioners argued that even if the law is ambiguous, the court should apply the rule of leniency, which states that the court should err on the side of the defendant when ruling on an ambiguous statute. The court disagreed stating that the BOP's method was a clear and natural interpretation of the statute and therefore could not be struck by the court.