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.