Quentin Capobianco, 18 (right), was accused of beating Jesse Smith, 29, to death with a hammer in Astoria on Jan. 12, 2015. View Full Caption Facebook, LinkedIn, DNAinfo/Trevor Kapp

QUEENS — A teenage Bitcoin trader beat his lawyer roommate to death with a hammer in their upscale Astoria apartment Monday afternoon during a fight about money, sources said.

But Quentin Capobianco, 18, says that he was acting in self-defense after victim Jesse Smith tied him up and held him at gunpoint and he managed to break free during the incident.

Capobianco told investigators that Smith, 29, confonted him about costly damages the younger roommate had made to their apartment in the Exo building at 26-38 21st St. about 3:30 p.m. Monday, sources said.

Then he claimed that Smith, a Hofstra Law graduate who worked for Morton Povman, P.C. — owned by longtime former Forest Hills City Councilman Morton Povman — pointed a shotgun at him and tied him up, sources said.

The teen managed to free himself, snatch a hammer and bashed his roommate over the head, he claimed to investigators, according to the sources.

Smith was pronounced dead at Elmhurst Hospital, police said.

Investigators found the hammer and shotgun, but are getting a warrant for a more thorough search and to confirm Capobianco's story, sources said.

The Morton Povman law firm, which is based in Forest Hills, declined to comment.

Povman served the Forest Hills area for 30 years before stepping down in 2001, according to published reports.

Capobianco and Smith were in business together trading Bitcoin, a type of online currency, according to state records and online at sites like LocalBitcoins.com and BTCjam.com.

They advertised that they would meet customers in person and sell the virtual Bitcoin for cash.

"We are here for you with speedy and reliable service (just ask our repeat customers). You get your bitcoins on the spot, we wait four days for them. We have a LOT of Bitcoins and an even BIGGER demand," the traders wrote on LocalBitcoins.com.

Numbers listed for Capobianco and Smith on the Bitcoin sites were not answered. Capobianco's family could not be reached for comment.

Smith, who was known to dress well, had once bragged to neighbors that he was a lawyer, but appeared to have started struggling recently.

"He'd always come in. He was a regular, but we hadn't seen him for awhile. He told us he was a lawyer. He said he used to work for other people, but now he worked for himself," said clerk at a nearby liquor store, Tony Wang, 31.

"He'd buy [Moet] champagne. He always dressed nice, but not the last few times. He said his business wasn't good. He looked rough, like he had a lot going on," Wang added.

Capobianco, who has no criminal record, was arrested at the apartment on charges of murder and criminal possession of a weapon, police said.

He was still awaiting arraignment Tuesday afternoon, prosecutors said.

Staff at a dry cleaners where the roommates had opened an account in October said Capobianco was reserved.

"They were both really fancy, wearing expensive clothes. Jesse talked directly. Quentin was kind of quiet," said dry cleaner Sylvia Barron, 46.

The Exo, where one-bedrooms go for $2,750, bills itself as an upscale apartment building with a roof deck and fitness center.

Smith visited a nearby deli just four hours before his death to buy cigarettes and iced tea.

"He said, 'Hi.' We asked, 'How is everything?'...He wore a suit and tie. I can'e believe it. I'm shocked. This is probably one of the last places he was," said deli employee Mohammed Alan, 19.

"He was a very good person. He was a lawyer. He said, 'If you ever have problems, call me,'" Alan remembered.