The victim has not yet been identified, but is assumed to be the grandmother of Rosa Hill's estranged husband, Eric Hill, police Lt. Glenn Moon said.
Police responded to the 7700 block of Peppertree Road around 6 p.m. because neighbors heard a loud argument and a possible gunshot coming from inside a residence, police Lt. Glenn Moon said.
Eric Hill, his 2-year-old daughter and his grandmother had been living at the home while Rosa Hill, 33, who is the mother of the 2-year-old, had been living in Oakland.
When police arrived, Rosa Hill and her mother Mei Li had allegedly been assaulting Eric Hill with an electric device and a collapsible baton, and threatening with a handgun to take the daughter, Moon said.
Moon could not confirm what the daughter's custody status was.
Eric Hill had expressed concern for his grandmother, who he had not seen since he got home and was confronted by the two women. Police searched the area and found the body, which is most likely that of his grandmother, in a shed near the home, wrapped and stuffed in a garbage can, Moon said.
Police allegedly found the gun on Rosa Hill and the electric device and the baton in the house.
They arrested the women, took Eric Hill to the hospital and took the daughter to a temporary foster home, Moon said.
When police set up a perimeter, they found Rosa Hill's father Ping Li, 67, parked close by outside.
Ping Li told police he dropped off his wife Mei Li at the house and was waiting to pick her up, Moon said.
Rosa Hill's vehicle was also parked in the surrounding neighborhood.
Ping Li, Mei Li and Rosa Hill are in Santa Rita Jail on charges of murder, attempted murder and conspiracy.
The daughter was not harmed, Moon said.
Police are waiting for an autopsy to figure out the identification of the person and how she died.
