Recap: Monday's Supreme Court Action

WASHINGTON (AP) - (AP) - A roundup of what's happening on Monday inside of the Supreme Court.

Court: Warrant needed for GPS tracking

The Supreme Court ruled unanimously Monday that police must get a search warrant before using GPS technology to track criminal suspects.

The GPS device helped authorities link Washington, D.C., nightclub owner Antoine Jones to a suburban house used to stash money and drugs. He was sentenced to life in prison before the appeals court overturned the conviction.

Associate Justice Antonin Scalia said that the government's installation of a GPS device, and its use to monitor the vehicle's movements, constitutes a search, meaning that a warrant is required.

"By attaching the device to the Jeep" that Jones was using, "officers encroached on a protected area," Scalia wrote.

All nine justices agreed that the placement of the GPS on the Jeep violated the Fourth Amendment's protection against unreasonable search and seizure.

Scalia wrote the main opinion of three in the case. He was joined by Chief Justice John Roberts and Justices Anthony Kennedy, Clarence Thomas and Sonia Sotomayor.

Sotomayor also wrote one of the two concurring opinions that agreed with the outcome in the Jones case for different reasons.

Justice Samuel Alito also wrote a concurring opinion in which he said the court should have gone further and dealt with GPS tracking of wireless devices, like mobile phones. He was joined by Justices Ruth Bader Ginsburg, Stephen Breyer and Elena Kagan.

A federal appeals court in Washington had overturned Jones's drug conspiracy conviction because police did not have a warrant when they installed a GPS device on his vehicle and then tracked his movements for a month. The Supreme Court agreed with the appeals court.

The case is U.S. v. Jones, 10-1259 .

Court overturns Calif. slaughterhouse law

The Supreme Court has blocked a California law that would require euthanizing downed livestock at federally inspected slaughterhouses to keep the meat out of the nation's food system.

The high court on Monday agreed that the state's 2009 state law should be blocked from going into effect.

California barred the purchase, sale and butchering of animals that can't walk and required slaughterhouses to immediately kill non-ambulatory animals. But justices said unanimously that the law encroached on federal laws that don't require immediate euthanizing.

California strengthened regulations against slaughtering so-called "downer" animals after the 2008 release of an undercover Humane Society video showing workers abusing cows at a Southern California slaughterhouse. Under California law, the ban on buying, selling and slaughter of "downer" cattle also extends to pigs, sheep and goats.