The U.S. Supreme Court Monday threw out a lawsuit against a Texas state trooper who shot and killed a fleeing driver while trying to disable the speeding car.

At a time of increased scrutiny focused on deadly police encounters, the justices cautioned that court decisions about whether officers improperly used deadly force must focus on the specifics of each case, not on broad generalities about police conduct.

Monday's decision involved the 2010 death of Israel Leija, Jr. during a high speed police chase on Interstate 27 in Texas. It began after a Tulia police officer approached his car at a drive-in restaurant on the night of March 23rd to tell him he was wanted on a previously issued warrant.

Leija sped away, and officers pursued him during an 18-minute chase that reached speeds of 85 to 110 miles an hour. While it was underway, Leija twice called the police dispatcher on his cell phone, claiming he had a gun and threatening to shoot at the police if they did not call off the chase.

Other officers decided to set up tire spikes at three spots along the interstate. At the first, beneath at overpass, Trooper Chadrin Mullenix of the Texas Department of Public Safety got the idea of trying to disable the car by shooting at it. He radioed for approval from his supervisor, who told him to stand by to see if the tire spikes worked first.

Nonetheless, Mullenix got out of his patrol car, took a position on the overpass, and fired six shots at Leija's car. After hitting the tire spikes, it rolled two and a half times. Authorities later determined that Leija was killed by Trooper Mullenix's shots, four of which hit him in the upper body.

When Leija's family sued, Mullenix argued that he was entitled to the legal immunity normally given to government officials when they act in the line of duty. Two lower courts disagreed, saying the case should go to trial.

But today, in an unsigned opinion, the Supreme Court agreed with the Texas trooper.

"Mullenix confronted a reportedly intoxicated fugitive, set on avoiding capture through high-speed vehicular flight, who twice during his flight had threatened to shoot police officers, and who was moments away from encountering an officer" at the overpass, the court said.

The doctrine of police immunity protects "all but the plainly incompetent or those who knowingly violate the law," it said, adding that its previous rulings have never said that the use of deadly force during a dangerous car chase is automatically a constitutional violation.

In the only noted dissent, Justice Sonia Sotomayor said Monday's ruling endorses a "shoot first, think later" approach to policing.

The trooper, she said, "fired six rounds in the dark at a car traveling 85 miles per hour. He did so without any training in that tactic, against the wait order of his superior officers, and less than a second before the car hit spike strips deployed to stop it."

Monday's decision was based solely on the written briefs submitted and without hearing oral argument in the case, a sign that a majority of the justices considered the issue so clear cut that further briefing and courtroom argument were unnecessary. The court issues a handful of such decisions each term.