Kennebec County Sheriff Randall Liberty calls it “my new normal.”

“If I get up in the middle of the night and I go to the bathroom and the window’s not covered, I feel like I’ve just exposed myself to enemy contact,” Liberty said in an interview this week. “That’s how my mind works now.”

He’s not talking about the bad guys of Kennebec County, dangerous as they may be from time to time.

No, when Liberty nervously steps away from that bathroom window at 3 a.m., he’s right back in the middle of Fallujah. Seven years after he last set foot in that hottest of Iraq’s former combat zones, his instincts still scream at him to take cover, to get out of harm’s way, to save himself while he still can.

And at the same time, back home in peaceful Maine, to save his fellow soldiers.

If you do one thing in the coming weeks to support Maine veterans who still are grappling with the demons they brought back from a war zone, take the time to see “A Matter of Duty, The Continuing War Against PTSD.”

The Maine Public Broadcasting Network documentary, co-produced by MPBN host Jennifer Rooks and documentary filmmaker Charles Stuart, will debut Friday at the University of Southern Maine. The hour-long film chronicles not only the reverberating trauma of war felt to this day by Liberty and a brave band of other Mainers, but also the weaving of a remarkable safety net for central Maine veterans teetering on the edge of disaster.

Liberty, who was a command sergeant major with the Army Reserve, led newly trained Iraqi troops into the Second Battle of Fallujah in 2004.

As he notes near the beginning of the film, over video he recorded with his cellphone while on patrol, “Nothing prepares you for the violence of war. Combat is a real combination of fear, deep sorrow, exhaustion, adrenaline, sleeplessness, and complacency to hyper-vigilance.”

Cut to the jarring image of a soldier bleeding from a gaping wound in his upper back.

“The violence is horrific,” Liberty continues. “The violence of a 50-cal or a mortar or a roadside bomb is just … it’s indescribable.”

Yet it’s war’s anticlimactic aftermath — in Liberty’s case, a return to a law-enforcement career that already had spanned more than two decades — that can pose an even bigger challenge for soldiers forever changed by a world gone mad.

Liberty’s PTSD might have gone untreated had it not been for his wife, Jodi, and his brother, Ron, who contacted the VA Maine Healthcare hospital at Togus when they realized his angry outbursts and other symptoms were getting worse, not better.

Cut to Liberty, dabbing at his eyes as he reflects on the emotional pain he endures to this day. At his side, listening sympathetically, is Dr. David Meyer, his VA psychologist.

“There, it was repressed,” Liberty says. “I was a sergeant major and, as a sergeant major, you’re the man. So you really can’t express those feelings (over) there.”

Here, though, the pain inevitably finds its way to the surface — sometimes therapeutically, sometimes not.

Rooks, who first approached Liberty about doing the film after he appeared with her on MPBN’s “Maine Watch,” said the sheriff’s candor at times caught her and co-producer Stuart by surprise.

“He puts it all out there,” Rooks said Tuesday. “He doesn’t think, ‘Hmmm, should I say this? Will it make me look bad?’ He doesn’t look at things that way. He gets it. By telling his story, he’s going to touch people in a way that others can’t.”

That said, Liberty’s personal story is just the beginning.

The film goes on to feature a “veterans block” Liberty created in 2011 at the Kennebec County jail. It’s reserved for inmates who have served in the military and, in a variety of homecomings gone bad, find themselves behind bars for everything from burglary to attempted murder.

Even as they await trial or serve their time, the onetime soldiers are plugged into a veterans support system aimed at getting them back on their feet once their legal troubles are behind them.

They also get cut a little slack: When Liberty and his jail staff realized that the sound of cells locking in quick succession sounded eerily like a machine gun firing, the automatic locking device was switched off.

Complementing the veterans block is the two-year-old Veterans Treatment Court, run by Justice Nancy Mills at the Kennebec County Courthouse — an innovative attempt to balance recent crimes against society with more distant service to country.

During an interview in her courtroom, Mills said, “The victim’s wishes are taken into consideration, certainly, by the district attorney and by me. But I’m happy to report that most of (the victims) understand that the veterans who are going into the program need help.”

The film’s real strength is rooted in the veterans themselves: the sheriff, determined to help others who share his emotional scars; the inmate who remembers losing eight battle buddies but can’t recall the beating that left him charged with aggravated assault; the female veteran who was raped by her fellow soldiers in a war zone and now anesthetizes herself with alcohol.

Most of their stories end on a hopeful note. One, tragically, doesn’t. Taken together, they give voice to a social crisis that will undoubtedly get worse before it gets better.

Standing outside a veterans shelter operated by Bread of Life Ministries in Augusta, Executive Director Dean Lachance ticks off the heightened risk factors — homelessness, physical and mental-health disabilities, substance abuse — that Maine’s returning veterans face.

“Our country, our communities, our nonprofits, our faith communities, are absolutely not prepared for the epidemic that we face today,” warns Lachance.

As if to underscore that point, the film concludes with 178 members of the Maine Army National Guard’s 133rd Engineer Battalion leaving Maine last month for a deployment to Afghanistan that will last until June.

“Here we go again!” the soldiers chant as they march, some for the second or third time, off to war.

And when it’s over, here again they will return.

The debut of “A Matter of Duty,” free and open to the public, will begin at 7 p.m. Friday at USM’s Hannaford Hall. The second public showing, one of many planned throughout the state, will follow on Nov. 8 at Colby College’s Ostrove Auditorium in Waterville. It will also air repeatedly on MPBN over the next two months, starting on Nov. 10 at 8 p.m.

In other words, you cannot — and should not — miss it.

It’s a story all of Maine needs to hear.

Bill Nemitz can be contacted at 791-6323 or at:bnemitz@pressherald.com