By Matt Leingang
and Kevin Aldridge
The Cincinnati Enquirer

Cincinnati firefighter Mark Kroth carries a bag of potentially contaminated items to a waiting sheriff's car Tuesday at the Hamilton County Courthouse. The Cincinnati Enquirer/GLENN HARTONG

An envelope of mysterious white powder shut down the second floor of the Hamilton County Courthouse on Tuesday afternoon, but the substance was not initially thought to be dangerous.

Members of the Cincinnati Fire Division's Hazardous Materials team bagged the powder and the envelope - which was addressed to Judge William L. Mallory - and sent the material to be tested at the Ohio Health Department's laboratory in Columbus. Results could be available today, state officials said.

The source of the envelope, which had no return address, was not immediately known. The incident is not being characterized as an act of bioterrorism, but the FBI was notified along with Michael Snowden, the county's homeland security project manager.

No one exposed to the powder reported any ill effects.

The powder was discovered about noon when Mallory was on the bench in his second-floor courtroom opening his mail. A trial had just recessed for lunch and there were about eight people in the room, said bailiff Steve Donnellon.

Donnellon, helping the judge with his mail, opened the envelope and passed it to Mallory, who looked inside, saw the powder and "immediately tossed it down on the floor," he said. Some of the powder dispersed across Mallory's desk. He called for court services, which then called the Fire Department, Hamilton County sheriff's deputies and the Cincinnati health commissioner.

Donnellon described the powder as a flaky, dandruff-like, white powder.

Everyone in the courtroom was sent home, ordered to bag their clothes, take a shower and report to a hospital if they felt strange or sick, Donnellon said.

"It kind of has everybody freaked," Donnellon said. "We are kind of on pins and needles.

The envelope also contained a threatening letter, said Steve Barnett, spokesman for the sheriff's department. It's not unusual for judges to get hate mail from prison inmates, Barnett said, but he could not recall another case involving unknown substances spilling out of envelopes.

Mallory's courtroom will remain sealed until the powder is identified, Barnett said.

E-mail mleingang@enquirer.com or kaldridge@enquirer.com