Investigators accuse Erianna's own mother and her boyfriend of killing the baby.
Documents filed in court reveal Erianna Beltran suffered injuries all over her body.
Three-year-old Erianna Beltran lived in this Southeast Fresno apartment with her mother Erin Skinner and her boyfriend Mack Lucas.
Lucas' mother tearfully defended her son and his girlfriend
Deanna Mitchell, Suspect's Mother: "They love their kids. This is devastating. Erin is on the verge of losing her mind right now. She's lost her children. She lost her freedom."
Both suspects are 19-years-old.
Investigators said Erianna arrived at Children's Hospital Central California last week.
Court documents indicate ... She was covered with bruises and a bite mark on her right elbow.
Erianna died two days after arriving at the hospital.
Fresno Lieutenant Shannon Galvez declined to say who she believes caused the death.
Galvez: "I can tell you both the mother Erin Skinner and her live in boyfriend Mack Lucas have been booked for the death of the child. They were in sole possession of the child when she suffered the injuries that caused her death."
People who lived near Lucas and Skinner called them great parents.
They never saw signs of child abuse.
Lenon: "I don't think they did it. I don't think so. They were too nice. They were friendly an everything."
Charges have not been filed against the two adults.
Two other children lived in the same apartment with Lucas and Skinner.
Officials say those kids are now in the custody of Child Protective Services.