Alfonzo Landa is charged as an adult in the Sept. 27 slaying of Andrew Garcia. He also is charged with attempting to kill six other people and carjacking.
The shooting came after a family party celebrating a baptism at a San Fernando Valley banquet hall.
Police say the baby died of a bullet to the head after Landa argued with a gang member standing outside the car and opened fire.
The gang member and a pregnant woman feeding the infant inside the car were injured. Four others near the car were not hit.
A second suspect remains at large.
Landa's bail was set at $9.05 million.