Boston Marathon bomber bought three pounds of black powder from N.H. fireworks store

The Boston Fire Department Hazardous Materials team clean the blast site near the Boston Marathon finish line one week after the FBI handed over Boylston street back to the city on April 22, 2013 in Boston, Massachusetts.

Boston Marathon bomber Tamerlan Tsarnaev walked into a New Hampshire fireworks store two months before his deadly attack and asked for the “biggest and loudest” kit in the store — then got another set free, the Daily News has learned.

In a chilling twist, the company that sold Tamerlan the fireworks is the same company that sold Times Square bomber Faisal Shahzad the firecrackers he used to build his failed car bomb.

“We were just shocked,” said Bill Weimer, vice president of Phamtom Fireworks in Seabrook, N.H. “After our Times Square experience, we said, ‘It can’t happen twice.’”

Tamerlan Tsarnaev was all smiles in 2010, but by 2013, he was plotting the Boston Marathon bombing, buying more than three pounds of explosive powder at a fireworks shop.

But it did. Weimer searched his company’s sales records last week and discovered Tsarnaev, 26, came into his Phantom Fireworks on Feb. 6 and was helped by a female store clerk.

“Like most 99% of the men who come in, he asked ‘What’s the biggest and loudest thing you have,’” Weimer said.

Phantom Fireworks in Seabrook, NH where 2013 Boston Marathon Bombers purchased fireworks.

The clerk directed him to a $199.99 “Lock and Load” kit, which contains four launch tubes and 24 black-powder-packed shells. The kits are advertised by the company as “barely legal.”

“Best mortar/canister kit you can get. The breaks are bigger, higher, louder than any other I’ve tried,” reports one reviewer on the Phamtom Fireworks website.

Fireworks purchased from Phantom Fireworks in Seabrook, New Hampshire by the suspected Boston Marathon bombers

Weimer said the kit packs the maximum power allowed under federal law for fireworks.

Tamerlan paid cash for the pyrotechnics.

An undated photo of Faisal Shahzad, who pleaded guilty for his plot to bomb Times Square

“For buying the kit, he got one free,” Weimer said. “So that’s a total of 48 shells.”

He said each shell contains roughly 30 grams of black powder — meaning the bombers would have more than three pounds of explosive power.

That’s enough for at least one bomb, experts said.

In this Sunday, May 2, 2010 file image taken from video, a police officer approaches the vehicle containing a car bomb, which stands with the door open and the police officer reaches down to lift one of the red canisters on the roadway in New York City's Times Square.

Weimer said he contacted the FBI as soon as he discovered sales records with Tsarnaev name on them.

He said the transaction did not initially raise red flags, calling “a totally unremarkable sale.”

That is until bombs exploded at the finishline of Boston Marathon on April 15, killing three people and injuring more than 200 people.