The U.S. Supreme Court yesterday handed police one victory and one loss, NPR reports. The justices limited the power of police to detain people who are away from their homes when police conduct a search. In a second case, the justices ruled that drug-sniffing dogs don't have to get every sniff right  for a search to be valid. The Supreme Court has long held that when police execute a search warrant, they may detain anyone found on the premises while the search is conducted. The purpose is to protect the officers' safety during the search and to prevent potential suspects from fleeing or destroying evidence. The new case asked whether that same rationale could be used to justify detaining residents of a home who were stopped about a mile away from the search scene. The answer was no.

In the dog case, the Florida Supreme Court said police must present field performance records to show that the dog is a reliable detector of the presence of drugs. The U.S. Supreme Court disagreed. Writing for a unanimous court, Justice Elena Kagan said requiring an inflexible performance checklist as the gold standard for canine reliability defies common sense. Instead, the justices said, courts should generally consider a dog sniff as reliable if the dog has completed and passed a certified training program that includes controlled performance tests. "This tells us that the Supreme Court is not going to interfere in the use of drug-sniffing dogs," said Orin Kerr, a law professor at George Washington University.