Menlo Park police received numerous reports of shots being fired on Willow Road and Bayfront Expressway around 7:45 p.m., according to Commander Dave Bertini.
As they reached the scene, however, they learned that shooting victims were located at the East Palo Alto McDonalds parking lot at Bay Road and University Avenue.
Officers arriving there found a car with five adults and one child.
The child, a 2-year-old boy, had been shot in the legs and had a grazing wound to his head. His mother, who had been holding him on her lap, also had been shot in the legs.
The mother and boy were taken to Stanford Medical Center with non-life threatening injuries. The other four adults in the car were uninjured.
Police determined that the victim vehicle had been driving on Willow Road when its occupants got into a dispute with another car.
The passenger in that car, described only as a green or dark green 2000s model Honda sedan, allegedly stuck a handgun out the window as the cars reached Bayfront and fired at the victim vehicle, Bertini said.
The suspect vehicle was last seen heading toward the Dumbarton Bridge.
Bertini said the incident was being investigated as potentially gang related, but investigators were not entirely certain of that yet.
A second, fatal shooting was reported in East Palo Alto on Capitol Avenue around 9 p.m., a short distance from the Menlo Park shooting, but Bertini said it appears to have been unrelated.