Police arrested 51-year-old Carmen Montenegro Sunday night in an Ontario neighborhood.
Investigators spent Monday excavating the property outside the home where the body is believed to have come from. A detective says they found what may be body fluids in part of the yard.
The home is about 200 yards from where Montenegro was spotted pushing the can and is owned by a relative of hers.
Police were looking into whether the unidentified victim was killed at the house or elsewhere.