The robberies started in January. There were 14 robberies in four months and according to police, they stole $8,000 worth of tools.
"They would go into a store and load up shopping carts and head for the door," Lt. Leonard Orman from Antioch police said.
The robbers were not armed with guns or knives, but rather, they used pepper spray when store clerks tried to stop them.
Police say they were discriminating, stealing only high end tools.
"Dewalt was one of the popular brands. There were a lot of drills, a lot of cordless equipment, stuff that's real popular right now," Orman said.
Investigators say the robbers sold the items in flea markets through a Bay Point man with an appropriate alias -- "The Tool Guy."
Antioch police were able to identify their getaway car. Last month, they arrested Trista Peterson at a traffic stop. Concord police arrested her brother Jessie Patrick and they nabbed Lester Burks earlier this month.
Tool thefts are on the rise in the Bay Area.
Andrew Banducci works for Matrix Heating and Air Conditioning. Thieves broke into his truck twice and took all of his tools. Now, his firm has installed heavy locks on the doors.
"So you close it, put the lock on because what would happen is they would either break the locks or break the window and just open the door and steal about $20,000 worth of tools," he said.
Banducci found some of his tools at flea markets.