SANTA MONICA, Calif.—Few details are known about the daily habits of James "Whitey" Bulger during the 15 years he lived in this seaside city before his dramatic arrest last week.

Still, some patrons of Sonny McLean's Irish Pub speculate that the alleged Boston crime boss must have come into their Santa Monica bar. After all, Sonny's, about two miles from the apartment Mr. Bulger shared with his longtime girlfriend, has been a gathering spot for decades for displaced Bostonians in Los Angeles.

Dimly lit with Red Sox and Patriots banners on its walls and framed photos of Larry Bird and Tom Brady hanging over its green upholstered booths, Sonny's seems far from the sunshine and palm trees of Santa Monica that surround it.

Capitalizing on the arrest, the pub last Thursday played and replayed the 2006 Martin Scorsese film "The Departed" on flat-screen televisions along the walls.

In the film, Jack Nicholson plays Frank Costello, a ruthless Boston crime boss who builds his criminal empire as he snitches on other crooks to the FBI. The character resembles Mr. Bulger—who allegedly neutralized rivals by informing on them to federal agents.

As the film played, patrons speculated, insisted or tried to remember whether "Whitey" had visited over the years. A chalk board in the men's bathroom at Sonny's read: "Whitey wuz here."

It would be hard to tell. Since he ruled Boston's rough Irish neighborhood known as "Southie" in the '70s and '80s, Mr. Bulger has lost much of the thick blond hair that earned him his nickname and grown a shaggy beard. An aging Irish-American with a Boston accent would hardly stand out at Sonny's.

Still, after word spread that Mr. Bulger, one of the FBI's most wanted fugitives, lived just down the road with $800,000 in cash stashed in the walls of his apartment and hand guns hidden in hollowed-out books, anything seemed possible.

"He had to have come in here for the clam bellies"—a New England specialty—said Joanie O'Hara Schecter, the bar's co-owner. "We're the only place in L.A. that has them."

Even before investigators were done carrying evidence from the apartment where Mr. Bulger lived, Bostonians last week arrived at the cream-colored building two blocks from the beach to smile and pose for pictures. Some wore shirts that read "Southie," another, "Harvard."

Later that day at the Los Angeles federal court building, Boston native Michael Patrick MacDonald waited outside the packed courthouse as the alleged mob boss was charged with racketeering, extortion and murder that could carry a life sentence.

"I don't know why I came. I just had to," Mr. MacDonald said. "I was remembering all the mothers who lost their kids in that neighborhood."

Mr. MacDonald was in Los Angeles adapting his memoir of growing up in the same south Boston neighborhood as Mr. Bulger into a screenplay. Part of the book, "All Souls," recounts how Mr. MacDonald's brother, a boxer in south Boston was killed in a botched robbery.

Mr. MacDonald said he was writing the scene in which Whitey meets his brother years ago when he heard about Mr. Bulger's arrest. He said he hoped to catch a glimpse of Whitey at the courthouse.

Later that day at Sonny's with two friends, Boston native and writer Dennis Lehane sipped a beer, occasionally glancing up at "The Departed" playing on a screen nearby. Mr. Lehane is the author of "Mystic River," a novel set in south Boston made into a movie starring Sean Penn. His story is rooted in the same violent culture that framed Mr. Bulger's own upbringing.

"I'm glad they got him," Mr. Lehane said of Mr. Bulger.

On the other side of the bar, "Big" Tom Nicholson, a solidly built native of Boston with a thick black goatee, drank a Budweiser and gazed up at "The Departed".

"I'm almost sad he got caught," Mr. Nicholson said of Mr. Bulger. "He was a legend in Boston. He comes from a time and a place that doesn't exist anymore in Boston…he reminds everyone of the old days, for better or for worse."

On the screen, Costello is splayed on the ground, gurgling blood and dying. His young protégé turned on him, ending a life of violence.

As Mr. Nicholson watched, most of the bar patrons had gone back to their beers and conversation. Mr. Lehane and his friends paid no attention.

Write to Timothy Lloyd at and Tamara Audi at