It's understood that Borton was known to the victims prior to the incident where he followed them into a nearby home.
The young girl had been chasing a cat when Borton approached her. He then struck her with a mallet which sent her flying across the room.
After a brief stoush, the girl screamed before he struck her again, this time caving her skull inwards and knocking her unconscious.
The screams from the girl alerted her mother who came to her aid, but was tragically killed when Borton struck her repeatedly with the mallet, fracturing her skull.
The young girl was then forced to watch her mother die as Borton undressed her and sexually violated her, telling her 'it's okay'.
Borton then returned to his own home where he showered before returning to the crime scene to clean the evidence.
When the girl woke he told her that it was an earthquake that had injured her mother and that she had been taken to hospital.
18 hours after the attack, he then phone emergency services admitting to killing the woman.
An autopsy showed that she had suffered at least eight separate head injuries, while the girl required surgery to reconstruct her skull.
During his trial Borton admitted plead guilty to all charges laid against him, which included murder, sexual violation, indecent assault, wounding with intent to cause grievous bodily harm and several theft charges.
He has been sentenced to life in prison with a non parole period of 19 years and has been placed on the sex offender list.
In his sentencing, Justice Simon France described Borton as having a 'very disturbed personality' and an 'incapacity to understand and empathise'.
Outside court Detective Constable Hayley Adams read out a statement prepared by the victim's husband and father in which he described the murder of his wife as 'numbingly awful'.
My daughter is still recovering and miraculously the prognosis is good he wrote.
Detective Senior Sergeant Warwick McKee described the case as the worst he had seen during his 30-year career.