Police do not know yet if the newborn was left there alive, or if the baby had already died before being placed there. Autopsy results should reveal that and more.
"Preliminary information from the coroner is that it appears to be a full-term female. Nothing on the race at this point," said Police Lt. Kelly Musgrove.
The dumpster is in the Parkside Apartments parking lot on Decoto Road in Union City. The baby was found by someone gathering recyclables. Police have ruled out pregnant women at the complex.
If the baby was born alive, it could have been dropped off at any fire station or hospital with no questions asked, through the state's Safely Surrendered Baby Law.
"It's probably not as well used or accessed as it should be," Assistant Chief Andy Smith told ABC7.
The 2001 law allows a mother or legal guardian to surrender a newborn within three days of birth. Both are given hospital bracelets with an identifying code, and the mother or guardian is asked to volunteer family medical history if known. They have 14 days to change their mind.
"It seems to be that it would be a shame to have it go any other way than a safe surrender of child. And, it's really to the benefit of the child and the mother. We will be nonjudgmental in our acceptance of the child," said Smith.
As of last June, 251 newborns have been safely surrendered. In addition to California, 46 other states have similar laws.