ProPublica’s multipart investigation on flawed federal and local law enforcement practices in the struggle against the MS-13 gang won the John Jay College/Harry Frank Guggenheim Award for Excellence in Criminal Justice Journalism. The multimedia package, by reporter Hannah Dreier and video journalist Nadia Sussman, was recognized in the “series” category of the prize, which is administered by the Center on Media, Crime and Justice at John Jay College.

Dreier’s first story, “A Betrayal,” published in collaboration with New York magazine, chronicled the story of a teenage informant who helped police arrest fellow MS-13 gang members only to have his life endangered when law enforcement turned over his file to immigration authorities.

A second piece, “The Disappeared,” in partnership with Newsday and “This American Life,” exposed the negligence and indifference of the Suffolk County Police Department on Long Island when confronted with a wave of nearly a dozen missing Latino teenagers. While the department ignored families’ concerns about their missing children, labeling the teens as runaways, it turned out that many of the missing had been murdered by MS-13 members. Within a week of publication, the Police Department announced that it will revisit cases in which families have alleged misconduct, and both of the detectives featured in our investigation are now under internal affairs review.

“The enterprise and hard work of these journalists shed light on some of the darker corners of U.S. law enforcement,” said Karol V. Mason, president of John Jay College of Criminal Justice, on this year’s award winners. “Their work makes clear the continuing importance of the role played by the media in helping Americans understand today’s criminal justice challenges.”

See a list of all the winners here.