Police were searching on Thursday for the arsonist who has set seven fires in Queens, releasing a surveillance video of a man in a hooded sweatshirt captured last month near one of the fires.

Investigators have already cleared two people wanted for questioning, including a first responder, and released two other videos.

The fires have all been set in a small area of Forest Hills from Nov. 8 to Dec. 6, mostly in homes under construction, police said, and they have damaged 13 different buildings. Two of the fires took place in a storage facility and in an empty building.

There have been no injuries as a result of the blazes.

In the most recent video, the suspect can be seen removing what appears to be a gun from his left anke and transferring it to his front pocket, police said.

"It is unusual. Usually pattern arsonists use an accelerant; there's not an accelerant here," Chief of Detectives Robert Boyce said earlier this week. "We've identified all construction, new construction in the area. Because that's what it seems to be."

Boyce said construction makes the home "more dangerous -- the wood is exposed, it goes up quick."

Police Commissioner Bill Bratton said on Monday the motive for these fires is unclear.

"I wish we knew," he said.

Investigators believe the person who is setting these fires lives nearby, adding the community is "very tightknit."

On Sunday, police also released a photo of a man on a motorcycle, seen near one of the fires. He was later identified as a first responder who saw the flames and tried to help.

"He had experience, he tried to help in case someone was hurt," Boyce said. "At that point he left. So he is no longer a subject of this investigation."

Police initially questioned another man after the arsonist left an encrypted note at a fire in November with that man's name. But investigators have since ruled him out.

Earlier this week, police added several dozen uniformed and plainclothes officers to the area, and started using technology to track the suspect, said Chief of Patrol Services Carlos Gomez. But Bratton declined to elaborate on what kinds of technologies the department would use.