The individual allegedly behind the recent suspicious mailings to Senate offices was arrested this morning.

The news, announced by Capitol Police spokeswoman Sgt. Kimberly Schneider in an evening statement, comes two days after Senate Sergeant-at-Arms Terrance Gainer told the Capitol Hill community the perpetrator was still at large.

Christopher Lee Carlson, 39, was taken into custody “at a home in the Portland-Vancouver metro area,” according to Schneider’s statement. The arrest was the culmination of an ongoing investigation by Capitol Police, the FBI, the U.S. Postal Inspection Service and local law enforcement.

According to a statement released by the FBI’s Portland Division, a federal grand jury in Portland, Ore., indicted Carlson on charges of “mailing a threatening communication to a Member of Congress” and “mailing a letter threatening to use a biological weapon to a U.S. Senator.”

Officials believe Carlson was behind the approximately 100 envelopes containing white powder and threatening letters sent over the past few weeks to dozens of Members of Congress in their state and Washington, D.C., offices.

Though Senators were the primary targets, at least one House Member, Speaker John Boehner (R-Ohio), also received a suspicious mailing.

“Anyone who sends threatening letters to government officials should expect to be found, arrested and prosecuted,” said U.S. Attorney for the District of Oregon S. Amanda Marshall.

All the mailings were postmarked from Portland.

Though none of the powdery substances have tested positive for hazardous materials, Gainer said accompanying letters warned that something harmful could be on the way.

“This recent episode serves as a real-world reminder of the importance of mail safety to the Senate community every day of the year,” Gainer wrote on Wednesday, referencing the anthrax attacks of 2001 and an incident with Ricin two and a half years ago.

Carlson will likely be arraigned in federal court on Monday.