When David Riley, a 19-year-old member of San Diego's Lincoln Park gang, was arrested in August 2009 on suspicion of shooting at a rival gang member, it received little or no public notice.
The same was true when Riley's first trial ended in a hung jury, and when he was convicted at a second trial of attempted murder and other charges and sentenced to 15 years to life in prison.
But now Riley’s name has assumed national legal prominence as one of two cases that led to Wednesday’s
"We got everything we wanted," said Stanford law professor Jeffrey Fisher.
The high court ruled 9-0 that police acted improperly when they seized Riley's smartphone without a warrant and discovered evidence used at his trial linking him to the gang and the shooting.
The decision does not free Riley from prison but it will allow his attorneys to seek a new trial on grounds that the original trial was "tainted" because of the phone information, said Fisher, part of the team that argued the case before the U.S. Supreme Court.
The unanimous ruling overturned a 2011 California Supreme Court decision that gave police the right to search cellphones without warrants.
In upholding Riley's conviction in 2013, a state appeals court said cellphone information was akin to things pulled out of a defendant's pocket during a post-arrest search and thus did not merit special protection.
Legal analysts said Wednesday's ruling would clearly apply to defendants whose cases are still pending in courts, but may not help those whose convictions are already final.
Lawyers said it has become common practice in California for police to search cellphones without warrants.
"There probably will be a good deal of litigation over whether this decision can be applied retroactively," said Dennis Riordan, an appellate criminal defense lawyer based in San Francisco.
Charles M. Sevilla, a San Diego appellate criminal defense lawyer, said those defendants whose convictions are final will face "an uphill battle" in trying to persuade courts to reexamine their cases.
But the restrictions are not likely to stop lawyers from trying. Lyn A. Woodward, who represented the losing defendant in the 2011 California cellphone case, said she intends to examine the possibility of reopening her former client's case.
The U.S. Supreme Court at that time refused to review the decision.
The 5-2 California Supreme Court ruling that was repudiated Wednesday was written by Justice Ming W. Chin, who said the search was legal under binding U.S. Supreme Court precedent.
Justice Kathryn Mickle Werdegar dissented, arguing that the precedents applied to searches of clothing and cigarette packages and were not analogous to phone searches. Former Justice Carlos Moreno joined her dissent.
San Diego attorney Edward Kinsey, who represented Riley at both of his trials, said the Supreme Court's decision is a victory for Riley and for the 4th Amendment protection against unreasonable search and seizure.
Too many court decisions in recent years have allowed exceptions to the protection, leading to a "rapid expansion" of authorities seizing information, he said.
But San Diego Deputy Dist. Atty. James Simmons, who prosecuted Riley, said the cellphone information "definitely was not the heart of our case. We also had witness statements, including his girlfriend who put him at the scene of the shooting, and his DNA on the weapon."
Chief Deputy Dist. Atty. David Greenberg said that if the 4th District Court of Appeals says Riley is eligible for a new trial, the district attorney's office will have to review the case in detail to decide whether to retry him.
Greenberg also noted that the Lincoln Park gang, loosely affiliated with the nationwide Bloods gang, is "a very violent gang that we've been prosecuting for a long time. Many people, innocent people, not just other gang members, have been killed by this gang."
In the Riley case, the rival gang member was not hit, although he crashed his vehicle. Along with attempted murder, Riley was also convicted of shooting into an occupied vehicle and assault with an automatic weapon. Two co-defendants pleaded guilty.
Riley was also convicted of pimping and forcing women into prostitution.
Perry reported from San Diego, Dolan from San Francisco.