Phoenix millworker William McBride is serving three years in prison after he pleaded guilty to arson charges.
McBride, 49, was convicted of three counts of arson in 2014.
He was sentenced to five years in federal prison in April, but the federal judge who sentenced him last month commuted his sentence to time served and time served without parole.
The U.S. attorney’s office in Arizona said McBride was arrested on April 6, 2015, on charges of arson, tampering with evidence and violating the criminal justice act.
McBride’s lawyers said he is not being held in jail because he is a citizen.
The U.N. Human Rights Council has called McBride a “serial arsonist” who has repeatedly burned the building.
The Phoenix Fire Department was called to the mill in January 2015.
The building’s roof was destroyed and the walls were covered in soot.
The mill’s owner, Jim O’Brien, filed for bankruptcy in February 2015, saying the mill had lost $3.5 million.