Taylor expects to spend a long time in a New Zealand prison but our criminal law might not permit that. Unless there is proof that he has done worse than post some mad messages online, it is hard to see him languishing in prison. Some of his comments, though, suggest he could be detained for treatment of another sort.
As a jihadist on Twitter he several times failed to turn off the cellphone function that gave away the location if Isis fighters, and after surrendering he told the ABC that among the hardships he faced was his inability to afford one of the Yazidi women captured by Isis. Any sympathy he might have found in this country probably evaporated on that admission.
Whatever New Zealand does with him, has to be exemplary. Taylor might be the first New Zealander known to have had his head turned by a fanatical cause promoted online but he will not be the last. Six or more are thought to have enlisted with Isis. But Isis will not be the last lost cause that excites susceptible minds.
Psychological studies of Taylor and any others that turn themselves in, might help policy and security services better understand the personalities and predicaments that pose a threat to public safety. They will certainly be under lifetime surveillance.
Supposedly repentant recruits, though, might pose less of a risk than Isis loyalists who have returned to Western homelands and gone underground. The caliphate is defeated but probably not dead in the minds of its adherents. They see themselves as soldiers in the service of centuries-old scriptural texts and prophecies they are convinced will come to fruition, not necessarily in their lifetime.
Wherever they wash up, they will need to be watched.