The Green Bay Fire Department says a letter sent to a Brown County judge contained a white powder that has been identified as calcium sulfate, more commonly known as drywall material.
The letter was opened by staff members of Brown County Circuit Court Judge Timothy A. Hinkfuss shortly before Noon.
The Brown County Sheriff's Department and Green Bay Fire then closed down the third floor of the building and ordered the three employees to undergo a decontamination process.
They were isolated for a time but were released once the powder was found to not be dangerous.
The loose white powder was tested by the Green Bay Fire Department, which determined it was drywall material.
The letter was addressed from an inmate at the Oshkosh Correctional Institution and WFRV-TV has learned the letter did contain a threat to the judge.
The third floor of the courthouse is still closed to business. The first and second floors of the courthouse remain open.
