A gun trafficking case out of Brooklyn is emerging as the next test over how much discretion federal judges have in setting prison sentences.

In two decisions this week, the U.S. Supreme Court offered judges greater leeway in deciding for how long to put criminals away. Neither case addressed the vexing question of whether more time can be tacked on just because the crime occurred someplace urban such as New York City, where the chances seem higher that innocent bystanders will be hurt any time a crime is committed. In other words, if judges are now more free to consider penitence, what then of population density?

That question is already at the center of a legal tug of war over how much prison time an elderly diabetic, Gerard Cavera, will receive for trafficking firearms. The judge in the case, Charles Sifton of U.S. District Court in Brooklyn, has sought to stick Cavera with a longer sentence than even the prosecutors sought. The judge argues that guns are generally more damaging in New York City than other areas.

“Firearms are less likely to cause harm in more rural areas, if only because they are less likely to cause harm to innocent bystanders,” Judge Sifton, who was nominated to the bench by President Carter, wrote at the time of the sentencing in 2005.

The 24-month sentence Judge Sifton set is not all that much more than the 18-month maximum recommended by the federal sentencing guidelines. Still, the 2nd U.S. Circuit Court of Appeals, which sits in Manhattan, rejected Judge Sifton’s stricter sentence, noting that it would create widespread disparities across the country for how people are sentenced for violating the same federal law.

In asking for Cavera to be resentenced, the circuit court wrote back in October that Judge Sifton “seems to devise and employ a formula requiring the length of sentences for gun trafficking to rise or fall with the population density of the locality where the weapons are expected to end up.”

The sentencing is expected to take place sometime next year. Cavera has been out on bail and living in Florida.

Until the Supreme Court decisions this week, there was little reason to expect that Judge Sifton would persist in recommending a sentence of more than 18 months.

Now, Cavera’s lawyer, Jeffrey Rabin, concedes that “a lot has changed.”

Criminal defense lawyers and prosecutors are watching to see if the Supreme Court’s case emboldens Judge Sifton to try again to get the longer sentence to stick.

“Judge Sifton may have ammunition now to follow what he did in the first place despite the 2nd Circuit’s ruling,” the attorney who represented Judge Sifton’s ruling on appeal before the 2nd Circuit, Daniel Hochheiser, said. “But that’s up to Judge Sifton and his understanding of the law.”

Judge Sifton has toyed with the idea of longer sentences for gun crimes involving New York for a long time.

A scholarly article on sentencing that Judge Sifton published in 1993 raises the possibility.