Why does a convicted killer get name suppression?

The Herald reports:

An Auckland grandmother who beat a 77-year-old man unconscious before setting him on fire will spend at least the next 15 years in prison.

The 48-year-old woman, whose name is suppressed, previously admitted the murder of Peter Lance Dixon, who was found dead in his South Auckland home after a fire in February 2012.

The High Court at Auckland yesterday heard the horrifying details of the killing, which Crown prosecutor Warren Cathcart called “calculated and callous in the extreme”.

The woman, who whimpered throughout, was jailed for life and Justice Rebecca Ellis imposed a minimum non-parole period of 15 years.

She’s been convicted and sentenced. Why does she have name suppression?