Meanwhile, a 33-year-old woman is before the Auckland District Court on two charges of being an accessory after the fact to murder.
“This is still very much an active investigation, and we are very interested in speaking to anyone with information that can assist.
“No piece of information is too small.
“There are people in the community that know exactly who was involved, and what happened. They need to do the right thing and speak up,” Baldwin said.
Whorrall’s mother, Carole Whorrall, travelled to New Zealand from the US after he was fatally attacked.
Carole Whorrall and her son Kyle, who was killed in an attack at a bus stop in the Auckland suburb of St Johns.
Speaking publicly for the first time since his death in May, she told the Herald about how she wanted her son to be remembered.
“Kyle was a brilliant, gentle and deeply caring person whose love for the natural world shaped his life and inspired those around him,” she said in a written statement.
“He was passionate about his work and admired greatly by his colleagues and friends, of which he had many.
“He was dedicated to making a difference and about to embark on a brilliant career. He was deeply loved and admired by his family.”
Police said anyone with information can contact police in confidence, and can attend their local police station, update them online now, or call 105.