In 257 out of 268 cases, agents in the FBI microscopic hair comparison unit offered flawed testimony. Even more, this number only represents a fraction of the cases that may have been affected by the flawed practices of these FBI agents. The practice has been underway for more than thirty years.

Now the Department of Justice has expanded its inquiry to review some 2,500 cases in which the hair comparison unit may have offered flawed testimony that was relied upon to obtain a conviction.

The Young Turks broke down how widespread the practice was and just what is being done now that the flawed practices are coming to light.