The following information comes from a DuPage County Sheriff's Office press release.
The DuPage County Sheriff’s Office is investigating a suspicious incident that occurred Monday afternoon at the DuPage County Courthouse, 421 North County Farm Road in Wheaton.
At approximately 1:15 p.m., a letter was received at the DuPage County Circuit Clerk’s Office. An employee opened a letter to find an unknown substance enclosed along with the correspondence.
The clerk notified deputies assigned to the courthouse, who then secured the clerk’s office and notified the Wheaton Fire Department to respond, according to the news release.
With the assistance of DuPage County Sheriff’s HAZMAT personnel, Wheaton Fire Department and FBI Chicago, all preliminary tests indicate the powdery substance is not harmful.
The investigation is ongoing and further updates will be made when information becomes available.