OAKLAND — Is a single, determined arsonist behind four massive construction fires that have scorched the East Bay over the past year, including a four-alarm blaze in Oakland Friday morning?

Two developers who were victimized in the earlier fires said Monday they’re convinced there is a pattern of arson.

Federal officials added to the intrigue Monday by releasing a shocking video of a hooded figure putting on gloves and scaling an Emeryville construction project two months ago, then scurrying away just as it bursts into flames. They described the figure as a “person of interest” in their investigation.

“I definitely think this is arson,” developer Rick Holliday said Monday of the latest blaze. “I think it’s the same person or group. The means and methods of setting the fire fits the exact pattern of both of my fires.” Holliday is developer of an Emeryville project that has been torched twice.

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Copycat? Second East Bay fire started in same spot inside building, developer says City officials and the Bureau of Alcohol, Tobacco, Firearms and Explosives offered no updates on the cause of the latest fire Monday as 22 members of the agency’s National Response Team arrived to begin their investigation. The ATF has declared the three earlier fires to be arson, but has not said they are linked.

“Our focus is to provide our expertise on fire scene analysis to the Oakland Fire Department for their investigation,” ATF Special Agent in Charge Jill Snyder said in a statement. “ATF approaches these scenes without any preconceptions about what may have happened, and we allow the evidence to guide us to a conclusion.”

No one was injured in the spectacular, early Friday morning blaze that destroyed a wood-framed structure, which was about 60 percent complete, according a spokesman for the developer, Wood Partners. The 328,000-square-foot Alta Waverly project at 23rd and Valdez streets was to contain 196 apartments and 31,500 square feet of retail space at the street level. As many as 900 residents in nearby buildings, including Oakland Police Chief Anne Kirkpatrick, were evacuated, though most were allowed to return home Sunday evening.

Holliday, whose mixed-use development just across the Emeryville border from Oakland burned down once last July and again in May, was out of town on vacation last week and only learned of Friday’s early morning fire later that night. He said he has not spoken to the owners of the large residential development two blocks from Lake Merritt.

“I strongly believe that there is a person(s) setting these fires for political reasons,” Holliday said, adding that details of the Emeryville fires and the latest Oakland blaze are quite similar.

The Emeryville fires both started in the same stairwell in the center of the development, Holliday said. While few details of Friday’s Oakland fire have been released publicly, the fire chief said the first arriving fire crews found flames coming from the center of the building construction.

Developer Athan Magganas agreed with Holliday, and said the fire at his building at 317-319 Lester Ave. on the east side of Lake Merritt in Oakland last Halloween had similarities.

Magganas said the arsonist at his building “breached” the second level of his building and spread accelerant in a stairwell, also at the center of his development.

“I bet you find out the same circumstances in this most recent fire,” Magganas said. “We’re vulnerable. We have been the target of these people … It’s become obvious when we’re hit, it’s all the same symptoms.”

All four fires were started in the early morning hours and when the buildings were at their most vulnerable — before flame-resistant sheet rock was added to the wood framing.

“They’re smart enough, these people, on knowing how to bring about the maximum destruction,” Magganas said.

Sam Singer, who has been speaking on behalf of the developers of the building that burned Friday, said they do not know any of the fire origin details yet.

“Construction was about 60 percent complete at the Alta Waverly building when the fire occurred, which is a vulnerable point in the construction cycle,” Singer said.

The ATF announced over the weekend a $110,000 reward for information leading to the arrest and conviction of anyone responsible for starting three fires at construction sites in Oakland and Emeryville earlier this year and in 2016. The agency also released photos of the mystery man in the video, riding a bike and wearing a dark hoodie.

So far, Singer said, that same hooded individual has not been spotted in video footage of Friday’s fire so far.

“To my knowledge, the bicyclist has not been spotted yet in the video footage,” Singer said. “There is a lot more footage to review and we do not have access to all the footage that the authorities are reviewing.”

Authorities have said the similarities between all these fires concern them, but they have not determined if Friday’s blaze is suspicious. All the projects had varying levels of security at the construction sites, including cameras.

A frustrated Holliday, who has vowed to rebuild, said he has received no updates on his latest fire.

“They are still in the active phase of sorting out leads,” he said.

Magganas, who has just started rebuilding his development, said the city of Oakland has created a “bureaucratic situation” that is fueling the problem by not allowing construction to continue at night when the arsonist has struck.

“We know security doesn’t quite do it, because all of these places had security,” Magganas said. “It takes more live beings, organisms being around to deter people.”

He said he understands construction noise would have to be stopped overnight, but there would be ways to keep workers there to keep buildings safe.

The city did not immediately respond to inquiries, but Singer said there were no issues and the Alta Waverly project had even been allowed to work on Saturdays.

Staff writer Rick Hurd contributed to this report.