Three fires in the last year, all at partially completed residential construction sites in Oakland and Emeryville, have all been ruled as acts of arson, and a fourth, which occurred in the early morning hours of Friday, seems likely to have been an act of arson as well. As the Chronicle reports, this latest inferno, which has temporarily displaced upwards of 700 people, appears to fit a pattern of deliberately set fires at partially completed buildings, including a pair of fires at the same site on the Oakland-Emeryville border in less than a year.

CBS 5 just aired surveillance footage that showed a suspicious person in a black hoodie, riding a bicycle, who arrived in the middle of the night on May 13 at the Emeryville site at 3800 San Pablo Avenue — footage that the ATF first released a month ago. As you can see in the video below, the man arrives at the site and scales some scaffolding, then quickly leaves on his bike just before the fire begins. The same project, dubbed The Interval, went up in flames less than a year prior, in July 2016.

Also, in the early morning hours of Halloween, October 31, 2016, a fire tore through an unfinished apartment complex near Lake Merritt. Like the fire on Friday, that fire was first reported around 5 a.m., and it destroyed the 41-unit building going up on the 300 block of Lester Avenue.

The question now is whether the same suspect could be responsible for all four of these fires — and the Chronicle also brings up a 2012 construction site fire at a senior housing complex in Oakland, suggesting a connection there.

Developer Rick Holliday, who's been building (and rebuilding) The Interval now for several years, said in May that this "feels like a war on housing in the East Bay," and he's not wrong.

Previously: Huge Construction Fire Near Oakland's Lake Merritt Causes Mass Evacuation