"I understand she was able to give the responding officers her first name but her condition was such that she died a short time later in hospital," Mr Turner said.
He said there was no indication of any sexual violation in the attack but confirmed the victim's denim skirt had been disturbed.
Police want to speak to the people responsible for the damage caused at the nearby Taupo Nui-A-Tia College where six windows were smashed about the same time as Miss Aim was assaulted.
"The longer those people are at large the more suspicious it looks for those involved. Our priority remains the solving of the murder case, not vandalism.
"We would ask again for those people to make contact with us," said Mr Turner.
Police did not think it likely Miss Aim had disturbed the vandals given the timeline established so far.
"She has left the Element bar shortly before 2am, gone to the BP garage at the intersection of Ruapehu and Heuheu streets arriving at 2am and leaving at 2.04am, heading towards Spa Rd on a walk we estimate to take 10-15 minutes.
"The alarm at the school was activated at 2.07am so we don't believe there was sufficient time for Karen to be at the school," said Mr Turner.
"We do know, however, that there was two taxis in the area where Karen was found and as well as a canvass of the bars we will be canvassing taxi companies tonight."
That bar canvass is scheduled to begin tonight, shortly after a blessing ceremony being held at the crime scene at 6pm.
"A memorial service is scheduled for early next week and arrangements are in place for Karen's aunt in the Manawatu to be able to travel up for that church service.
"We have no suspects so far and the team is working very hard to identify Karen's movements before she died and this has all the makings of a particularly difficult murder inquiry," Mr Turner said.
"But we have a team of about 50 staff from across the North Island working on the case and I am confident of a successful resolution."
- NZPA
