Officers responded to the shopping center in the 1000 block of East Capitol Expressway at about 9:30 a.m. after receiving reports of a shooting, police spokesman Officer Jose Garcia said.
The man and the woman each had at least one gunshot wound and were pronounced dead at the scene.
Investigators have since determined that the two victims had a previous dating relationship, Garicia said.
The female child found unharmed inside the vehicle was the couple's daughter, police said.
The female child found in the vehicle was taken into protective custody by Santa Clara County Child Protective Services, police said.
Police did not release the names of the victims pending notification of their relatives.