Universal City, Calif. ? There’s a strong Northern Irish accent — coming from James Nesbitt — on BBC America.

He plays opinionated undercover cop Tommy Murphy in the rough-edged drama “Murphy’s Law” (beginning its second season 8 p.m. Monday); Nick, the amoral seducer in “The Miller’s Tale,” an explicitly sexy adaptation from Chaucer’s “Canterbury Tales,” (7 p.m. today); and Adam, the contrary, often naked lover with commitment problems on “Cold Feet,” a series about three emotionally troubled couples (8 p.m. Sundays).

“He has such screen presence, which absolutely fits into our brand of being unique,” says BBC America President Bill Hilary.

Grinning broadly, his eyes flashing with amusement, Nesbitt says he’s been advised to “talk a bit slower” when speaking to the press. He was here to promote his BBC America shows at a gathering of TV writers.

But he didn’t talk any slower. He’s a gabber with a charm comprehensible in any language.

Nesbitt’s “Murphy’s Law” character was written for him by novelist Colin Bateman.

“We come from similar working-class Protestant backgrounds,” says Nesbitt, 40, who grew up in a country split by the conflict between Protestants and Catholics.

“Colin was one of the first writers to begin writing with humor about the situation … to throw off, I suppose, the shackles of fear,” Nesbitt explains. “The humor born out of the (conflict) is often quite dry, quite acerbic, quite laconic.”

Murphy’s humor is definitely dark, but then so is his history. He was a Royal Ulster Constabulary officer whose daughter was murdered by the Irish Republican Army.

That bleak back story, Nesbitt says, makes the policeman’s move to England and undercover work entirely understandable, “because he’s running away from that and running away from himself. Being able to immerse himself in other characters is his way of not dealing with the past.”

Married to actress Sonia Forbes-Adam and the father of two daughters, Nesbitt was born in Coleraine, County Derry, where his father was headmaster of his primary school. His three older sisters are teachers, and he thought that would be his career path, too.

But he performed at Irish festivals, played “The Artful Dodger” when he was 13 at a local theater, and had his equity card by the time he was studying French in college.

“One night at 4 in the morning when I was struggling with a very, very overdue essay on ‘Les Mains Sales’ by Sartre, I thought it was time to give it up,” he says.

Soon he was attending the Central School of Speech and Drama in London.

His films include “Welcome to Sarajevo” and “Waking Ned Devine,” in which he played farmer Pig Finn. He portrayed the Protestant civil rights activist and Parliament member Ivan Cooper in “Bloody Sunday,” the 2002 docudrama about the 1972 massacre of Irish protesters by British troops.

Still, Nesbitt wondered whether he chose the right career path — until he did “Bloody Sunday.”

“Is it a serious job?” he says. “Is it something someone should be doing?

“When I made ‘Bloody Sunday,’ for the first time I realized that it did have worth and maybe I could achieve something in it, and that I really did enjoy it, and maybe I should allow myself to enjoy it.”