According to police documents, officers found Pettibone with stab wounds to the neck, and the toddler was found dead from a gunshot wound.
Police reportedly found a 9mm handgun inside the home that is believed to have been used in the shooting. Further inspection of the weapon found a bullet had been loaded backwards into the magazine, causing the gun to jam and not fire again.
One of the responding officers reported that Pettibone admitted that she "shot her baby and tried to kill herself."
Pettibone was taken to the hospital for her injuries, and was released from the hospital on Monday. Once released, she was immediately arrested by police.
Pettibone has been booked into jail on second-degree murder charges.
According to the Department of Child Safety, no previous reports of abuse, neglect or abandonment were ever made involving Pettibone or the child. Officials also say no other children were in the home.