Police and federal authorities are investigating what may have been a bomb sent to Arizona Sheriff Joe Arpaio, one of the most well-known and controversial sheriffs in the country.
A postal worker in Flagstaff became suspicious of a package addressed to Arpaio, 80, Thursday. The Bureau of Alcohol, Tobacco, Firearms and Explosives told ABC News that the package held a container and what appeared to be gun powder. Tests are underway to determine if the package was a working, viable explosive.
Arpaio's office said in a statement that a bomb team had been deployed, and the device was neutralized.
Authorities already had "investigative leads," according to the Maricopa County Sheriff's Office. Flagstaff police, the FBI and U.S. Postal inspectors are investigating.
The potential explosive device follows shortly the killings of another law enforcement officer and prosecutors. Two prosecutors have been gunned down in Kaufman County, Texas, since January. Last month, Tom Clements, chief of the Colorado prison system, was killed in his home.
Arpaio, dubbed "America's Toughest Sheriff," was elected sheriff of Maricopa County in 1992 and since then has garnered national headlines with his views, to name few, on immigration, prisoners' rights and gun control.
Arpaio's latest controversy came weeks after the Newtown, Conn., mass shooting, when he deployed armed volunteers to patrol schools in the Phoenix metropolitan area.