The case of Adnan Syed, who served more than 20 years in prison on murder charges before his conviction was vacated on Monday, is unique because of the enormous publicity it garnered through the hit true-crime podcast Serial. But one of the reasons he was set free — because prosecutors withheld evidence that may have exonerated him — is not uncommon.
In making the decision to release Syed from prison, Circuit Judge Melissa Phinn in Baltimore relied on an extensive review of the case by prosecutors in Maryland showing, among other things, that authorities knew of at least two alternative suspects besides Syed in the 1999 murder of Hae Min Lee, an ex-girlfriend of his.
But prosecutors kept information about alternative suspects from defense attorneys, according to a motion to vacate the conviction filed by prosecutors. They now have 30 days to decide whether to proceed with a new trial or drop the charges against Syed, who has long maintained his innocence.
Syed's case highlights how the withholding of potentially exculpatory evidence by police and prosecutors can often lead to wrongful convictions. Critics say that a lack of accountability and transparency has made it easy for prosecutors to get away with such official misconduct, as innocent individuals brought before the justice system are made to pay — oftentimes with years of their lives behind bars — for crimes they did not commit.
Withholding potentially exculpatory evidence violates a key legal principle
Such conduct is a violation of what is known as the Brady rule, which requires prosecutors to turn over any evidence that could help exonerate a criminal defendant.
In the motion to vacate, two Brady violations were cited: the prosecution's failure to disclose evidence pointing to any alternative suspect and the failure to disclose that one of the suspects in the original investigation had threatened to kill Lee.
"Considering the totality of the evidence now available, the information about an alternative suspect would have been helpful to the defense because it would have helped substantiate an alternative suspect defense that was consistent with the defense's strategy at trial," prosecutors said in their motion.
Cases in which prosecutors don't follow the rule are "shockingly common," says Vanessa Potkin, director of special litigation at the Innocence Project.
"It's not just a Baltimore problem, it's not just a Maryland problem. This is something that is pervasive throughout the country," she says.
There were at least 2,400 exonerations in the U.S. between 1989 and 2019, and in 44% of cases it was the withholding of potentially exonerating evidence that resulted in a prisoner's release, according to a 2020 paper from the National Registry of Exonerations.
"Prosecutorial misconduct and police misconduct are the most common contributing factors" to exonerations, says Simon Cole, director of the registry. "And within that, the concealing of evidence, which is what's alleged in [Syed's] case, is the most common subtype of official misconduct."
Prosecutors have a lot of leeway
In many jurisdictions, prosecutors can keep their files secret and the decision over what to turn over to the defense is left up to the prosecutors themselves, says Laura Nirider, co-director of the Center on Wrongful Convictions at Northwestern University's Pritzker School of Law.
"We must rely on individual prosecutors to decide which pieces of evidence to disclose to the defense and which pieces of evidence to withhold," she says. "It can be difficult for any prosecutor to objectively decide what evidence is truly material and truly exculpatory."
In a 2017 interview with NPR, the journalist and Yale University law professor Emily Bazelon compared the situation to something akin to the honor system.
"We're talking about a situation in which they can see what's in their files, but the defense can't see it. And the judge can't see it either. So they're really making this very important call on their own."
But there is an ongoing push to implement more open discovery, says Nirider.
"These are systems in which prosecutors allow defense attorneys to take a look at their files in a much more broad way," she says. That would "ensure that Brady material gets turned over and to ensure that defendants like Adnan can mount the most robust and fairest defense that's available to them."