The shooting occurred in the 3400 block of Gregory Drive in the unincorporated town of Bay Point sometime before 1:45 p.m. Graciela Gutierrez, 34, was killed by the gunshot wound she received in the chest, county officials said.
Valladolid's 3-year-old son, Christian, was injured during the incident and was airlifted to Oakland Children's Hospital where he remains in critical condition.
Detectives believe Valladolid went into the home, where he shot Gutierrez and Christian before fatally shooting himself in the head.
The sheriff's office said there was a temporary restraining order against Valladolid, a Pittsburg resident.
