The Supreme Court on Thursday ruled that reckless criminal conduct doesn't qualify as a violent felony under the Armed Career Criminal Act, a federal law that mandates longer sentences for firearms possession convictions if a person has previously been convicted of three violent crimes.

In a split 5-4 decision, the court decided in favor of criminal defendant Charles Borden Jr.'s stance that one of the three violent felony convictions the government cited in seeking a sentence under the ACCA did not fall within the scope of the law, since it was a crime involving reckless, instead of purposeful conduct.

Justice Elena Kagan delivered the judgment for the court, which was joined by Justices Stephen Breyer, Sonia Sotomayor and Neil Gorsuch. Justice Clarence Thomas wrote a concurring opinion.

The court's decision turned on whether an offense with reckless mens rea, or intent, can fit within the ambit of "violent felonies" under the ACCA. The law mandates a 15-year minimum sentence for individuals found guilty of illegal gun possession if they have at least three violent felonies already on their record. Under the elements clause of the law, an offense qualifies as a violent felony if it involves "the use, attempted use, or threatened use of physical force against the person of another."

Offenses criminalizing reckless conduct don't fit within that definition, Justice Kagan wrote, since the use of force "demands that the perpetrator direct his action at, or target, another individual."

"Reckless conduct is not aimed in that prescribed manner," Justice Kagan said, warning that reckless offenses being treated as violent felonies would impose larger sentences on "individuals (for example, reckless drivers) far afield from the 'armed career criminals' ACCA addresses."

The government had sought an ACCA sentencing enhancement after Borden pleaded guilty to illegal gun possession. One of the three crimes prosecutors invoked was a reckless aggravated assault conviction in violation of Tennessee law.

Borden argued that this offense did not satisfy the ACCA guidelines on violent felonies, since a mental state of recklessness sufficed for that assault conviction, rather than purposeful or knowing conduct. The district court, however, rejected the argument and sentenced him as a career offender. The Sixth Circuit affirmed the judgment.

The Supreme Court's decision on Thursday reversed the ruling and remanded it for further proceedings.

Justice Gorsuch and Justice Thomas were the only conservatives to side in Borden's favor. Justice Thomas said in his concurring opinion that "the particular provision at issue here does not encompass petitioner's conviction for reckless aggravated assault."

But he argued that "the consequences of [Thursday's] judgment are at odds with the larger statutory scheme" of the ACCA and the result of a previous precedent that trimmed the ACCA in a way that Justice Thomas believes should not have happened.

While Borden's aggravated assault crime did not qualify as a violent crime under the ACCA's elements clause, it does under the law's residual clause, Justice Thomas said. The residual clause of the ACCA defines conduct that presents a serious potential risk of physical injury to another as a violent felony.

The high court, however, ruled the clause was unconstitutionally vague in 2015 and thus unenforceable, a decision Justice Thomas said was "wrong" and should be overruled.

In a dissenting opinion, Justice Brett Kavanaugh claimed the plurality's opinion in "real-world terms" will leave out cases in which a person consciously disregards risks, such as reckless driving, that causes harm. The opinion was joined by Justices John Roberts, Samuel Alito and Amy Coney Barrett.

Justice Kavanaugh zeroed in on the plurality's interpretation of the ACCA elements clause, claiming the phrase "against the person of another" has "zero to do with mens rea."

"That phrase instead reflects a centuries-old term of art in the criminal law that distinguishes offenses against the person from offenses against property," he said. "Even if the phrase 'against the person of another' did not reflect a longstanding term of art, the ordinary meaning of the statutory phrase 'use of physical force against the person of another' — just like the phrase 'use of physical force' — encompasses reckless offenses such as reckless assault and reckless homicide."

Justice Kagan responded by noting that "if Congress had used the word 'recklessly' in the elements clause, we would have to interpret that clause to cover reckless offenses, even though the best reading of the clause without that word goes the other way."

"But Congress did not say 'recklessly.' And we must construe the elements clause as it is—without first inserting the word that will (presto!) produce the dissent's reading," she said.

The case attracted attention from a number of defense associations. The National Association for Criminal Defense Lawyers wrote in an amicus brief that upholding the Borden judgment would've had devastating implications for criminal defendants.

Counsel for Borden declined to comment, citing the case's pending status. The U.S. Department of Justice did not immediately return a request for comment from Law360.

The petitioner, Charles Borden Jr., is represented by Erin Phillipi Rust of the Federal Defender Services and Kannon K. Shanmugam of Paul Weiss Rifkind Wharton & Garrison LLP.

The government is represented by acting U.S. Solicitor General Elizabeth Prelogar.

The case is Borden v. United States, case number 18-5409, in the U.S. Supreme Court.

--Editing by Peter Rozovsky.