The justices on Monday unanimously approved the Arizona law's most-discussed provision requiring police to check the immigration status of those they stop for other reasons. But it struck down provisions allowing local police to arrest people for federal immigration violations. They also warned against detaining people for any prolonged period merely for not having proper immigration papers.
The decision left police chiefs and sheriffs grappling with questions ranging from what justifies reasonable suspicion that someone is in the country illegally to how long officers must wait when federal authorities are slow to respond to a question on someone's immigration status.
"It's uncharted territory," said Tony Estrada, sheriff of Santa Cruz County on the state's southern border with Mexico. "It's going to be challenging. It's a complicated issue, and it's not going to be solved by this particular decision."
Tucson Police Chief Roberto Villaseñor estimates the statute will result in 50,000 additional calls a year to federal immigration authorities in his city alone. That includes 36,000 arrests a year for suspects who are not booked into jail, typically for offenses like disorderly conduct, misdemeanor assault, shoplifting, vandalism and driving more than 25 mph over the speed limit.