The robber carries a gun, he's not afraid to use it and he apparently doesn't need the cover of darkness to strike.
Kirkland police hope a recently released video of one of the robberies will help them put the gunman behind bars for good. In that video, the heavily-disguised man tells a Shell station clerk to open the cash register and hand over the money.
The same scene had been repeated more than a dozen times, most recently on Wednesday at a Kirkland Shell station.
Cesar Garcia was working at the station, and he knew right away what was happening.
"He come in and show me the gun and asking only for the money," Garcia said.
Garcia said in addition to demanding money, the robber asked him for a pack of Marlboro cigarettes.
"I don't know, it's too much risk for a little money," he said. "I don't know what this guy's thinking."
The Texaco next door also got hit, and this week store owners posted the robber's picture on every door.
"We just want to catch him. Our cashier at the time, our evening cashier, was very brave, gave him what he wanted," said Texaco's Darcy Dinwiddlie.
Nobody has been hurt so far, but business owners know that could change in a moment's notice.
"Who's to say what could happen? Dinwiddie said. "This guy seems cool with what he does. It's frequent, it's you know, back to back. Don't know what his story is."
Investigators say the same man has robbed at least 18 businesses in Kirkland, Bellevue, Redmond, Everett and Renton.
The robber is described as a white or Hispanic male ranging in age from 25-30 years old, 5'2" to 5'6", with a stocky build. Anyone with information about the man is asked to call police.