James 'Whitey' BulgerAP

Imprisoned gangster James "Whitey" Bulger has been writing letters from his Plymouth, Mass., jail cell to his former California neighbors, reports the Boston Herald.

So far, at least three people who either work or live at the Princess Eudgenia apartments, Bulger's old hideaway, have received hand-written missives signed "Charlie," after the mobster's alias Charles Gasko.

“It seems like now he’s started to write letters to people because you know now he’s very lonely,” said Birgitta Farinelli, senior manager of the Embassy Hotel Apartments, which owns the building where Bulger stayed with his girlfriend, Catherine Greig, for most of his 16 years on the run.

READ MORE:

Whitey Bulger Halloween costume offends families of victims

Whitey Bulger posed as illegal Irish immigrant for years

One of the gangster's former neighbors says he plans to reply to Bulger's letter.

“I’m keeping the letter, and I plan on writing him back eventually,” said the neighbor, who requested anonymity. “I wasn’t that surprised that he wrote me, because we got along.”

One of Bulger's first letters from the jailhouse went to Enrique Sanchez, superintendent of the Embassy Hotel Apartments.

“He signs it Charlie. He signs it like how we knew each other, as friends,” said Sanchez.

He declined to show the letter.

“Absolutely not. He’s my friend. I don’t want to betray his confidence. It’s between us,” he said.

Bulger's former neighbors are still shocked that the man they knew was a gangster on the lam.

“We didn’t know anything about this — we found him a very nice man, and I was shocked. I could not believe it,” Farinelli said.

Said Catalina Schlank of her former upstairs neighbors: “To me, they were good people. I don’t associate them with mafioso or the underworld. They don’t ever show me a bad side.”