The Fairfield man accused of shooting at and damaging three Central Maine Power substations in Kennebec County in February was charged Wednesday with destruction of an energy facility, a federal crime punishable by up to 10 years in prison.

The FBI began investigating Thomas Welch, 54, after he turned himself in and admitted to firing dozens of bullets at substations in Winslow, Windsor and Augusta in the early morning hours of Feb. 15. He was initially charged with aggravated criminal mischief and aggravated reckless conduct.

The shootings injured no one, but caused more than 10,000 people to lose power for a brief time, including 8,500 in Winslow.

According to an affidavit from FBI special agent Richard Whisman, Welch’s vehicle was seen on security footage near the Augusta substation. Investigators found casings matching his ammunition at all three sites.

The damage to the substations, a CMP representative told Whisman, totaled “several million dollars.” Spokespeople for both CMP and the Maine Public Utilities Commission declined in February to comment on the total damages.

The FBI’s investigation spanned more than a month after the shooting and included interviews with four witnesses, including the man who accompanied Welch when he turned himself in and one of Welch’s brothers.

Witnesses told Whisman that Welch had been stockpiling guns and ammunition in the weeks before the shootings, including at Welch’s Fairfield metalworking business, Mainely Handrails. Police seized thousands of rounds of ammo and dozens of guns from his apartment the afternoon following the shootings.

A witness also told Whisman that Welch had stopped taking his anti-depressant medication in the days leading up to the shootings and had recently struggled to maintain his sobriety.

Whisman wrote in his affidavit that Welch told several members of his family and two friends about the shootings the next morning before he turned himself in. Welch never explained his motive, Whisman wrote.

But, he wrote, the shootings came after a series of concerning posts on Welch’s Facebook account.

Two months before his arrest, Welch wrote a post criticizing media attention to mass shootings. He said the goal of such coverage was to paint “good gun owners” in a bad light, and called the coverage “psychological warfare” that “some of us are waking up from,” while others “are going to be good peasants to the government.”

In several posts, Welch lamented the state and federal government for imposing taxes and sending defense funds to Israel.

“Everyday I’m getting more angry, as more of the curtain is getting pulled back,” he wrote in September. “I’ve voted since the day I became old enough. I now know that none of my votes mattered!”

In December, Welch reposted a clip from the conservative commentator Tucker Carlson’s podcast, in which Carlson and Shawn Ryan, another conservative commentator, discuss taxation “in a country that has more (expletive) guns and ammunition than anywhere else in the world.”

“We’re moving toward totalitarianism or revolution — violent revolution,” Carlson says in the clip. “By the way, if you tell people they can’t say what they think, and that their vote doesn’t matter, how many options have you left for them?”

Two days before the shooting, Welch posted screenshots of the definitions of the words “civil disobedience” and “obedient,” under which he commented, “are you fine with complying to our Corrupt State and Federal Government?”

On the morning of the shooting, the cover photo on Welch’s account was a photo of him holding and aiming a rifle, Whisman wrote in his affidavit.

No initial appearance has yet been scheduled for Welch’s new federal charge. He remains in the Kennebec County Jail on $250,000 bail from the state charge in February.