The American Canyon Middle School and the Donaldson Way Elementary School were locked down at 10:30 a.m. for about an hour while deputies searched for the suspect, Capt. Tracey Stuart said. Both schools have reopened.
The gunman fired a shot from a semi-automatic handgun into the wall behind the female clerk in the small store located at 3915 Broadway around 10:20 a.m., Stuart said.
He demanded money and left with an undisclosed amount of cash. No one was injured in the robbery, Stuart said.
The suspect is a man in his 20s, who is about 5 feet 4 inches tall, Stuart said. He was wearing a teal hooded jacket or sweatshirt over a black shirt and a black mask. He also was carrying a teal backpack.
Anyone with information about the robbery is asked to call (707) 253-4591.