SEATTLE – A Selah, Wash., man has been charged with threatening to kill Democratic Sen. Patty Murray over her support for federal health care reform, leaving voicemail messages at her office saying she had a target on her back and “it only takes one piece of lead.”

Federal agents arrested Charles Alan Wilson, 63, without incident in Yakima, Wash., on Tuesday.

Murray’s office in Seattle reported the threats amid a rash of ugliness aimed at lawmakers who supported the health care legislation. Some lawmakers have been spit on, and several have reported receiving threatening calls.

FBI spokesman Bill Carter said Wilson is believed to be the first person in the country arrested in connection with such threats.

The messages to Murray were left on voicemail from a blocked telephone number, FBI Special Agent Carolyn W. Woodbury wrote in a probable cause statement. Agents said they traced the calls to Wilson’s home in Selah.

Wilson has a .38-caliber revolver registered to him and has a concealed weapons permit, Woodbury wrote.

To confirm Wilson was the caller, one agent telephoned him and posed as a member of a group working to repeal the health care legislation, the statement said.

According to an excerpt of the conversation, Wilson confirmed he repeatedly called Murray as well as Washington’s other Democratic senator, Maria Cantwell. He then stated: “I do pack, and I will not blink when I’m confronted.”

Murray’s office told the FBI it had been receiving harassing messages from the caller for months, but they became more threatening as Congress was voting on the health care legislation.

“There’s a target on your back now,” said one message March 22. “It only takes one piece of lead. Kill the (expletive) senator! Now that you’ve passed your health care bill, let the violence begin.”

In another message over the next several days, the caller said, “I want to (expletive) kill you.”

Wilson made an initial appearance at federal court in Yakima on Tuesday on one count of threatening a federal official. He was appointed a public defender for the hearing and ordered to be kept in custody, pending a detention hearing set for Friday.