The first robbery took place May 28 just before 3 p.m. at a Shell gas station in the 500 block of International Boulevard. The second occurred June 18 at about 10:20 p.m. at the Lakeshore 76 gas station in the 3200 block of Lakeshore Avenue.
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The suspect is considered armed and dangerous, police said. He's described as a black man with light complexion, about 5 feet 6 inches tall and 140 to 160 pounds, and in his early to mid 20s.
A second suspect, police said, is believed to be the getaway driver. The car is described as a light green, late 1990s model, four-door Honda.
Police have offered a reward of up to $5,000 for information leading to a conviction in the case.
Anyone with information is asked to contact the Oakland police robbery section at (510) 238-3326.