In person, Cris D’Annunzio is a gentle, soft-spoken man. Sweet, even. So you might not suspect that he was the son of a minor Mafioso. Although, as he says, “This is the cross you have to bear when your name ends in a vowel.” And then he adds in a warning growl, “Watch your stereotypes!”

D’Annunzio delivers this cautionary warning on the stage of the Ruskin Group Theatre in Santa Monica, where he is currently telling his family’s story in a moving, chilling, hilarious one-man show called “Digging Up Dad.”

As the story begins, D’Annunzio is shoveling dirt from his father’s grave in an angry and futile attempt to come to terms with his ambivalent feelings about his dad, and to put to rest the mystery of his death. For his father had died in bed at the age of 48, when Cris was 12, from what was determined to be a “lethal dose of opiates.”

“But my father didn’t do drugs,” D’Annunzio says. “He was an alcoholic, but he didn’t do drugs.” He was also a small-time bookie and dabbler in the stock market, and he hung out with his cronies at the Italian-American Progressive Club, often tending bar there. “They were just a bunch of regular guys,” D’Annunzio says, refusing to believe the stories he heard about “organized crime, the Mafia, La Cosa Nostra …”

But slowly he came to the realization that his father had been murdered, and at the insistence of his mother, “the drama queen,” he went to his father’s apartment to look for clues. To his amazement, he discovered bank statements that revealed that his father had accrued some $250,000. Not likely for a small-time hood.

Nevertheless, D’Annunzio took the money, which provided him with a nice apartment in California and a new BMW, which, he says, “put me in the game, made me a player.” He had begun a not-very-successful career as a stockbroker for Shearson Lehman Brothers in Beverly Hills, but now the money gave him new confidence. “I still didn’t know what I was doing, but I looked like I did,” he says.

Until he was “discovered” by two guys who began to extort the money from him at the rate of $15,000 a week. Panicked, he paid until he was almost out of money, and then a quick call to his mother took care of the problem. His mother, who is still alive and kicking at 67, was apparently even more “connected” than his father, he told me when I interviewed him a few days before his show opened.

I had seen him before, when he played the defense attorney in “Mutiny at Fort Chicago” last summer at the Ruskin. I was struck at the time by how much he resembled Kevin Spacey. And apparently Spacey thought so, too. In fact, the two men not only look alike, they have the same birthday as well. (What are the odds!?) Which might have influenced Spacey when he chose D’Annunzio to play the lead in “Cobb,” Lee Blessing’s 1989 play about the celebrated Detroit Tigers outfielder. (That play ran some eight years ago at the Falcon Theatre in Burbank.)

But football, rather than baseball, was D’Annunzio’s forte. He played the game while getting his BA in History at Princeton and spent a year playing for the Buffalo Bills after he graduated. When he moved to California and decided that being a stockbroker was a “fairly miserable” job, he began to hang out with a group of actors he met on Santa Monica’s Third Street Promenade and began to pick up small acting jobs.

By the time he auditioned for Spacey he had started to think about writing and performing his one-man show, and Spacey encouraged him to continue with it. And so “Digging Up Dad” was born.

And a powerful and mesmerizing show it is. D’Annunzio is magnificent, performing brilliantly and with great virtuosity, moving from anger to fear to poignant childhood memories of his beloved “Grampa”, who immigrated to America and then went back to Italy at the outbreak of World War II to look after his mother, an Italian Jew. They both wound up in a Nazi concentration camp, where “Grampa” survived the Holocaust. His mother did not.

D’Annunzio is abetted onstage by Mike Myers’ fluid direction and offstage by his wife Goldie, who gave birth to their fourth child — and first son — the night before the show opened. Vincenzo Anthony Gabriele D’Annunzio provides assurance that the family name will carry on for another generation. And “Digging Up Dad” will, hopefully, allow Cris D’Annunzio to finally put his family demons to rest.

“Digging Up Dad” will continue Fridays and Saturdays at 8 p.m. and Sundays at 2 p.m. through March 20t at the Ruskin Group Theatre, 3000 Airport Ave. in Santa Monica. Call (310) 397-3244 for reservations.

Cynthia Citron can be reached at ccitron@socal.rr.com.