Letter containing white powder sent to McCain campaign office

A threatening letter containing an unidentified white powder was sent to a John McCain campaign office in this south Denver suburb Thursday, authorities said. They later said the substance was not hazardous.

A letter sent to a McCain campaign office in New Hampshire initially was reported to also contain threatening language and white powder. Authorities said that was a false alarm and there was no powder in that envelope.

Both the New Hampshire and Colorado offices were evacuated.

At least 19 people were examined at hospitals or were quarantined outside the office here while authorities tried to determine whether the powder was hazardous. Everyone had been sent home by late Thursday, said Arapahoe County Sheriff Grayson Robinson. He said that the substance was not hazardous but that it would take days to determine what it was.

Andy Lyon of Parker-South Metro Fire Rescue Authority said the return address on the envelope listed the Arapahoe County detention center and the name of an inmate.

Sheriff’s officials identified the inmate as Marc Harold Ramsey, 39, who has been incarcerated since September 2007 on investigation of felony menacing, harassment and second-degree assault on a peace officer.

Ramsey may face federal felony charges in Thursday’s incident, sheriff’s officials said.

Malcolm Wiley, a Secret Service spokesman in Colorado, said there was no powder in the New Hampshire envelope. He said he did not know about the content of the letter.

It had a Denver return address, which alarmed staffers in Manchester, N.H., who had heard about the Colorado incident.

Bruce Williamson of the Arapahoe County Sheriff’s Office said authorities took the incident “very seriously” because the Democratic National Convention begins Monday in Denver.

McCain is the presumed GOP presidential nominee.