She died soon after receiving a heavy blow to the front of her face, while she was lying on the ground.
Broughton was arrested less than a week later after police recovered the blood-stained bat, and a digital camera and the burned remains of a handbag belonging to Ms Aim.
Broughton is presently serving a 12 1/2 year sentence after pleading guilty to murder, as well as one count wounding with intent to cause causing grievous bodily harm to another woman.
In court today, Mr Manunui was unable to answer Coroner Dr Wallace Bain's questions as to whether Broughton was under the influence of drugs and alcohol when he murdered Ms Aim.
Dr Bain described the act as "shocking" and said it was "very generous" Ms Aim's father, Brian Aim, still saw New Zealand as a "very beautiful" country.
Dr Bain told the court how parental supervision was a major underlying factor in the murder, and that better supervision could stem crime in society as a whole.
He reserved his findings, which are expected to be released within a fortnight.