TALLAHASSEE — Siding with a Broward County sheriff’s deputy who fatally shot a man, the Florida Supreme Court on Thursday unanimously ruled that law-enforcement officers can use the state’s “stand your ground” self-defense law as a shield against prosecution.

Justices upheld the dismissal of a manslaughter charge against Deputy Peter Peraza, who contended that he acted in self-defense and, as a result, was immune from prosecution under “stand your ground.” Peraza in July 2013 shot Jermaine McBean, a man with a history of mental illness who had pointed an air rifle at officers, according to the Supreme Court.

In an 11-page opinion, Justice Alan Lawson wrote that two parts of the controversial “stand your ground” law make clear that a “person” is justified in using deadly force and does not have a duty to retreat if that person believes it is necessary to prevent death or great bodily harm.

“Because these statutes plainly and unambiguously afford Stand Your Ground immunity to any ‘person’ who acts in self-defense, there should be no reason for further analysis,” Lawson wrote, going on to cite an earlier court case and a dictionary definition. “Put simply, a law enforcement officer is a ‘person’ whether on duty or off, and irrespective of whether the officer is making an arrest. Although neither of the two statutes defines the word ‘person,’ it must be given its ‘plain and ordinary meaning.’ In common understanding, ‘person’ refers to a ‘human being,’ which is not occupation-specific and plainly includes human beings serving as law enforcement officers.”

The Supreme Court took up the issue after conflicting opinions from lower courts about whether law-enforcement officers could use the “stand your ground” law. The 4th District Court of Appeal agreed with Peraza, but the 2nd District Court of Appeal came to a different conclusion in an earlier case.

Attorney General Pam Bondi’s office urged the Supreme Court to go along with the 2nd District Court of Appeal and rule against allowing officers to use the “stand your ground” defense. Bondi’s office contended that police are subject to an older law that can provide what is known as “qualified” immunity.

“It’s two different laws that have two different procedures, and that’s what this fight comes down to — which procedure applies,” Melanie Dale Surber, a senior assistant attorney general, told the Supreme Court during oral arguments in August.

Lawson wrote that the 2nd District Court of Appeal made a “good faith attempt to ferret out what the Legislature ‘intended’ when it enacted a defense that partially overlapped a pre-existing defense.” But he said the “plain language” of the “stand your ground” law clearly resolved the issue.

The Peraza case stemmed from an incident in which police received a report of a man walking down a street openly carrying a gun. Peraza and another officer pursued McBean and ordered him to stop and drop the weapon, according to court records. The man did not drop the weapon, leading Peraza to fatally shoot him. The weapon turned out to be an air rifle.

Peraza was indicted on a charge of manslaughter with a firearm but used a “stand your ground” defense. Under the law, a circuit judge held a pre-trial evidentiary hearing before siding with the deputy’s self-defense arguments. The 4th District Court of Appeal later upheld that ruling.