PORTLAND — A Portland man who authorities say mailed anonymous letters threatening to shoot Gov. Paul LePage is in jail on federal charges.

Michael R. Thomas, 50, who has no apparent criminal record in Maine, was arrested by the FBI on Friday after a DNA sample from the stamp of one of the letters matched Thomas’ DNA profile.

He is charged with mailing threatening communications, which is punishable by as much as five years in prison.

According to a court affidavit prepared by FBI Special Agent Pamela Flick, a letter mailed Jan. 6, the day after LePage was inaugurated, said: “As far as I’m concerned you’re the devil himself and I will put a bullet or two in you, if it’s the last thing I do. I’m willing to sacrifice my life just to make sure you die … I will strike when you least expect it.”

The single-spaced, typed letter, all in capital letters, also said: “I did not vote for you and as far as I’m concerned you are not my governor. Now I’m ready to vote with a bullet … Thank God for our second amendment remedies. I’ve got you in my cross-hairs …”

The unsigned letter had no return address, but had been postmarked at the Southern Maine Processing and Distribution Center in Scarborough, according to court papers.

The letter was given to the FBI, which sent it to its Questioned Documents Unit in Quantico, Va.

Another letter, mailed March 1, said only: “What good is government if words have no meaning?” and “P.S. Communists don’t miss.”

A third letter, mailed March 11 and received three days later, was filled with expletives.

It called the governor “ignorant” and “arrogant” and said he should be burned alive. “Blessed is he who spills your blood,” it said.

That letter was given to the Maine State Police crime lab.

On Thursday, Erin Miragliuolo, a forensic DNA analyst with the state lab, matched the DNA profile taken from a section of the stamp on the letter with a profile that was in a federal database from a previous case.

The DNA matched with a person named Shawn P. Higgins, a suspect in a case in 2005 in which white powder accompanied a threatening letter mailed to Austin Preparatory School in Reading, Mass. The letter had been processed by the eastern Maine distribution facility.

According to the court filing, Higgins legally changed his name on May 17, 2005, in Aroostook County to Michael Rafael Thomas.

Thomas was not accused of sending the letter in 2005 because the U.S. Postal Inspection Service said a sample from the stamp did not match his DNA profile. There wasn’t enough material on the envelope to test, investigators concluded.

But Thomas’ DNA profile, which he may have given voluntarily, was still accessible when the current investigation began.

Miragliuolo said in the court papers that the odds against a false match are 22.2 quadrillion to one.

The State Bureau of Investigation shows no criminal record for Thomas under either name. Cumberland County’s unified criminal court shows no criminal cases against him.

Thomas lives at Loring House, a subsidized housing complex on Brighton Avenue for senior citizens and disabled people. The nature of Thomas’ disability is not clear, but he breathes with an oxygen tank, neighbors said.

They also said he generally keeps to himself in his one-bedroom apartment.

The affidavit in U.S. District Court in Portland was filed in support of a search warrant seeking new biological samples from Thomas, from which to develop a fresh DNA profile, and to seize computers and printers that may have been used to generate the letters.

Residents at Loring House said federal agents were seen leaving Friday with large bags full of items they believed came from Thomas’ room.

LePage’s press secretary, Adrienne Bennett, said in a prepared statement Monday: “This was the result of a combined effort from the Maine State Police Executive Protection Unit, Maine State Police Crime Laboratory and Federal Bureau of Investigation. We appreciate the diligence from federal officials regarding this matter and we will continue to fully cooperate with the ongoing investigation.”

The governor’s office referred all questions to the FBI.

Three days after the third threatening letter was received by the governor’s office, Bennett announced that LePage was expanding his executive protection detail to include a uniformed trooper outside his office.

At the time, she said that the decision was related to the changing political climate, and that there had been no additional threats to the governor.

In late January, a Penobscot County Jail inmate was charged with terrorizing after detailing a plan to kill the governor and slipping it under his cell door. Leroy Dunn, 29, pleaded guilty Feb. 28.

It’s unclear whether the decision to increase security was related to the letters attributed to Thomas. Bennett said Monday that the governor’s staff does not comment on security measures.

Thomas is scheduled to appear in court Wednesday for a detention hearing, at which he can ask to be released on bail.

His court-appointed attorney, J. Hilary Billings, said Monday that it was too early to discuss the substance of the case, but the government will seek to hold his client without bail.

Staff Writer David Hench can be contacted at 791-6327 or at: dhench@pressherald.com