Available on DVD: “The Imposter”

We’ve all wanted at some point in our lives to become someone else, to shed our troubles and responsibilities and start afresh.

French-Algerian con artist Frederic Bourdin made a career of it, assuming throughout the 1990s a series of more than a dozen alter egos that took him across Europe on false passports.

Bourdin’s greatest con brought him in 1997 to America and to a traumatized family in San Antonio, who welcomed the 23-year-old interloper into their home as their long-lost son, Nicholas Barclay, a boy who vanished one day in 1994 when he was 13.

The mother of all stranger-than-fiction yarns, Bourdin’s Texas con is meticulously retold in director Bart Layton’s gripping, hair-raising documentary The Imposter.

Layton turns up the weird by having Bourdin, the most unreliable of unreliable narrators, recount his story for us and play himself in the clever dramatic reconstructions.

Bourdin gets under your skin.

"For as long as I remember, I wanted to be someone else. Someone who was acceptable," he says. "Nobody ever gave me a childhood, because to give a kid a childhood you need to love that kid."

Finding himself in Linares, Spain, in 1997, Bourdin decides to seek shelter at an orphanage. Grilled by the authorities, he lets out that he’s American. So begins the con.

A resourceful manipulator and a great storyteller, Bourdin recounts how he called the National Center for Missing & Exploited Children in Virginia to find a missing boy whose identity he could steal.

He picks Nicholas, despite their age difference.

To our astonishment, Nicholas’ family immediately accepts Bourdin as their beloved child. No matter that Bourdin is a dark-haired, brown-eyed, olive-skinned adult with dark stubble, while Nicholas was a blue-eyed, blond child with pale skin.

Everyone buys the lie, including the Spanish authorities, the U.S. Embassy in Madrid, and the FBI agent assigned to track down Nicholas’ supposed abductors. (Bourdin claims he had been kidnapped by an international sex slavery ring.)

If The Imposter provides a measure of insight into Bourdin’s pathology — he was the unwanted child of a 17-year-old French girl and an older Algerian man — it provides a searing, laser-sharp emotional portrait of Nicholas’ family, including his mother, Beverly Dollarhide, and his sister Carey Gibson.

Both refuse to accept the FBI’s later findings that Bourdin is a fraud — his fingerprints yield a thick Interpol file detailing his previous scams. It’s unnerving to learn that he always impersonates children.

The Imposter  shows how our beliefs, our sense of truth, are more often shaped by our desires — for love, affection, revenge, closure — than by the facts.

The film leaves us with a couple of nagging questions: Is Bourdin lying to gain our sympathy when he tells about his own traumatic, loveless childhood? Did the family have an ulterior motive for so readily accepting the imposter?

Layton’s dazzling film is an exciting, edge-of-your-seat experience superior to any Hollywood mystery you’re likely to see for a long time.