Revenge and a desire for notoriety are among reasons someone would set fire to remote skifield buildings in the middle of the night, according to an expert on criminal profiling.
Dr Ian Lambie, of Auckland University, said if Friday night's arson attack at Whakapapa was motivated by revenge, police would have to work out who the culprit had a grudge against - the skifield operator, a current or former staff member, or someone else.
It was also possible the arsonist was a copycat inspired by the Australian fires. "You are making a pretty big statement to set fire to skifield buildings on Ruapehu in the middle of the night knowing they'll almost definitely burn down before help comes."
Copycat arsonists often feel inadequate and are driven by the notoriety and sense of power they derive from starting fires. Other arsonists set fires to conceal evidence of a crime, or, very rarely, because of delusions caused by a psychiatric illness.
Firebugs are usually male.