NEW YORK (CBSNewYork) — A man arrested in connection with a deadly package explosion at a Queens home last summer appeared federal court Thursday.

Victor Kingsley faces charges of using a weapon of mass destruction and illegal transport of explosives.

On Wednesday, the NYPD, FBI and bomb squad descended on the home of the 37-year-old, with specially trained agents carefully removing evidence.

It’s a house, the FBI and NYPD Joint Terrorism Task Force say, was headquarters for bomb making.

Terry Johnson remembers Kingsley as a quiet teen.

“He pretty much was just anti-social,” said Johnson. “My heart hurts, man.”

Neighbors were shocked to see the swarm of officers descend on East 43rd Street in East Flatbush, a house Kingsley shares with his mother.

“Every day she prays with everyone, she greets everyone,” one neighbor said. “I can’t even imagine something like that going on in her house.”

Authorities say up until last month, Kingsley was ordering bomb making materials like a remote controlled fireworks firing system from Amazon, CBS2’s Magdalena Doris reported.

Investigators say in July, Kingley sent a bomb to a home in Springfield, Queens addressed to an NYPD officer.

“We believe the bomb was retaliatory for an arrest of 2014 that happened on this very block,” said NYPD Chief of Detectoves Robert Boyce. “He was in possession of a stun gun at that time.”

But the officer he allegedly intended to target didn’t live there. Instead, the 73-year-old landlord of the home, George Wray, opened the box which sat outside the home for days.

After it exploded, Wray died four days later with 80 percent of his body burned.

Deputy Police Commissioner John Miller called Wray “an unintended and innocent victim of this cowardly attack.”

“He died a violent and extraordinarily painful death,” he said.

Wray’s wife was grateful for the arrest.

“I am happy they arrested someone, hopefully it’s the right person,” she said. “But I’m happy.”

Kingley faces a possible term of life in prison if convicted.