March 10, 2012 - 11:02 AMT
Man sending threatening letters to U.S. congressmen arrested

A 39-year-old man charged in connection with threatening letters containing white powder that were sent to members of Congress and some media organizations was arrested Friday, March 9, AP reported.

Investigators said Christopher Lee Carlson was indicted on two criminal counts arising out of an investigation into the mailing of about 100 envelopes containing white power.

The letters, postmarked in Portland, Ore., so far have all tested negative for toxic substances, the U.S. Attorney's office in Portland said.

The U.S. Capitol Police said in a statement that Carlson was arrested at a home in the Portland area.

Carlson was charged with one count of mailing a threatening communication to a member of Congress. House Speaker John Boehner, R-Ohio, was referenced by name. The second count charged the man with mailing a letter threatening to use a biological weapon to a U.S. senator. Sen. Barbara Mikulski, D-Md. was named in that count.

Carlson is expected to be arraigned Monday.

Investigators have recovered more than 100 letters addressed to U.S. senators and representatives. The Seattle office of Sen. Patty Murray, D-Wash., said it also received one.

"Threatening letters - whether hoax or real - are serious concerns that federal law enforcement agencies will aggressively pursue," said Greg Fowler, special agent in charge of the FBI in Oregon.

Murray's office did not immediately return a call for comment Friday night.