Federal prosecutors in Manhattan will not bring criminal charges in the case of an unarmed black teenager who was shot to death in his home by a white New York City police officer, officials said Tuesday.

The Southern District U.S. attorney’s office said prosecutors found a lack of evidence to pursue federal charges in the 2012 death of Ramarley Graham and have officially concluded their investigation. The 18-year-old was shot in the bathroom of his Bronx home by an officer who had barged inside during a drug investigation.