LOS ANGELES-When federal officials recently confirmed the existence of a massive National Security Agency program that has been collecting Americans' phone data for years, they argued it was needed to fight terrorism.
But that acknowledgment has opened potentially seismic rifts in the nation's legal system, allowing defendants to argue that the government is holding a massive trove of evidence that is necessary to their cases - the same kind of evidence that, when it's collected by police, is commonly turned over to defendants.
As a result, one south Florida case has become a surprise center of focus in the debate over secret government surveillance.
"This falls into the category of 'you have to be careful of what you ask for,' " Jonathan Turley, professor at George Washington University Law School, said of the NSA's phone-monitoring program. "The government asked for complete storage of data for all citizens, and they got it. Now they're in possession of a unique resource of information."
Since the end of May, Terrance Brown has been on trial on suspicion of masterminding a Brinks armored-truck robbery in south Florida that left a man dead in October 2010.
Phone data have long been used in court to show what defendants were doing - and where they were - at the time of a crime. In Brown's case, the FBI used phone data to compile maps that show that at least one of Brown's co-defendants had apparently made calls in the same multiblock area where a series of robberies related to the case were committed.
Investigators weren't able to find all the relevant data for Brown's phones, because his carrier apparently didn't keep records covering the entire span of the crimes.
Last Sunday, after federal officials acknowledged the NSA trove, Brown's attorney, Marshall Dore Louis, filed a motion asking the NSA to turn over Brown's phone records.
"The records are material and favorable to Mr. Brown's defense," Louis wrote, adding that the request was "not intended as a general fishing expedition."
On Monday, U.S. District Judge Robin S. Rosenbaum asked the Justice Department to file a response by Wednesday so that she could decide on Brown's request. Her deadline was later extended a week.
Rosenbaum added that she would review the legality of any NSA data gathered on Brown as part of the surveillance dragnet affecting the nation's phone users.
A spokeswoman for the U.S. attorney's office in southern Florida said prosecutors planned to file a response by the judge's deadline but declined to say whether it would oppose Brown's motion. A Justice Department spokesman said the request for NSA data appeared to be the only one of its kind - at least for now.
"I think that the government is going to be very aggressive in snuffing out this request," said Turley, noting that a successful bid for the NSA's records would open the floodgates for other defendants seeking otherwise unavailable phone records for their cases. "The acknowledgment of the program has been a true game-changer for litigation."
Jameel Jaffer, the ACLU's deputy legal director, said the government will have to pay the price eventually.
"That's one consequence of building these kinds of databases, is that people are going to want to know what's in them for all kinds of reasons," Jaffer said. "Sometimes they'll have a constitutional right to know what's in them."