"America's toughest sheriff" will escape criminal charges after the federal government dropped its probe into the Arizona lawman. Maricopa County Sheriff Joe Arpaio has been under investigation by the U.S. Justice Department for abuse of power related to cases he brought against a judge and two county officials who were at odds with him, The Associated Press reported. Arpaio, who was voted into office in 1992, has denied any wrongdoing and has cooperated with authorities. Assistant U.S. Attorney Ann Birmingham Scheel released a statement Friday saying her office "is closing its investigation into allegations of criminal conduct by current and former members of the Maricopa County Sheriff's Office and the Maricopa County Attorney's Office." Arpaio remains under investigation by the U.S. Justice Department in a separate civil case brought by a group of Latino plaintiffs who accuse Arpaio and his deputies of engaging in racial profiling.