An independent inquiry into the way police dealt with a Christchurch party that ended in two murders has found officers could not have prevented the tragedy.
Hannah Rossiter and Jane Young, both 16, were killed after Lipene Sila drove his car through a crowd of partygoers standing on Edgeware Road.
Sila was found guilty of murdering the teenagers and will spend at least the next 17 years in prison.
The Independent Police Conduct Authority launched its inquiry after police received complaints that they acted too slowly to shut down the party and clear the hundreds of young people off the road.
Officers were donning riot gear 100 metres away from the party when Sila hit the two girls.
In releasing its report on Thursday afternoon, the authority says there was no relationship between the timing of police actions and the deaths.
Canterbury Superintendant Dave Cliff says he is pleased with the inquiry's outcome, saying the tragedy could not have been foreseen.
"It is extremely pleasing on the part of police to know that the incident was handled absolutely as well as it could be. We are proud of the fact that our staff handled it so well."
However, Mr Cliff says the underlying issue of teenage drinking should be addressed and wants the age limit for purchasing alcohol raised.
He acknowledges the timing of the report may be difficult for the families of those involved, but says the decision to release it so close to Christmas was made by the authority, not police.