The man who died after being assaulted at an Auckland bus stop has been identified by a colleague as US PHD student Kyle Whorrall.
Police said the motive for the attack was still unknown, but believed someone in the community knew the two offenders involved.
Detective Inspector Glenn Baldwin said they were seeking witnesses in a white Toyota ute, which was driving in a westerly direction along St Johns Rd, and cut off by a black SUV, which u-turned in front of it.
They believe the black SUV was involved in the crime, and they would like help to identify its occupants.
The occupants of the white ute are critical witnesses, Baldwin said.
Baldwin said Whorrall, 33, went to the supermarket about 9.40pm and walked 400m to the bus stop.
He then sat at the bus stop, and did not flag down a bus that was in the vicinity.
The stop was not his usual one. It was only a few minutes later that he was attacked, Baldwin said.
"He was subjected to a senseless attack by people in a black SUV," Baldwin said.
Police have been contacted by a number of people but are still seeking witnesses in the vicinity of St John's Rd before 10pm.
Baldwin said police were not ready to release Whorrall's name and were still contacting family overseas.
Baldwin said police believe the weapon was "a long one".
Baldwin said police are seeking to identify the occupants of the black SUV and that there was potentially a third person in the SUV at the time of the attack.
Auckland's Deputy Mayor Desley Simpson said she understood Whorrall was a PHD student at the University of Auckland. He had been studying entomology.
She said she had passed on her condolences to the university.
A tribute on Facebook said Whorrall was working on his dissertation at the university.
"I'm sure all of his friends, family, and colleagues are in shock, as I am. Senseless and tragic," it said.
The university did not want to comment when approached by RNZ.
