The FBI still has not assessed whether its facial recognition systems meet privacy and accuracy standards nearly three years after a congressional watchdog—the Government Accountability Office—raised multiple concerns about the bureau's use of the tech.

Since 2015, the FBI and other law enforcement agencies have used the Next Generation Identification-Interstate Photo System, which uses facial recognition software to link potential suspects to crimes, pulling from a database of more than 30 million mugshots and other photos.

In May 2016, the Government Accountability Office recommended the FBI establish checks to ensure the software adhered to the Justice Department's privacy and accuracy standards, but according to a report published Wednesday, the bureau has yet to implement any of the six proposed policy changes.