Hi Helen,
Fantastic news, and thanks very much for sharing it.
Many of these Police Gazette's have more than one Index which can be confusing to those who haven't seen them before.
Taking the New Zealand Police Gazette 1916 Vol 41 as an example, there is a:
General Index.
Index of Discharged Prisoners (includes crime, year of birth, description, native of, scars, etc.)
Index of Persons Summarily Convicted.
Index to Photographs (from 1886).
All indexes are alphabetical.
TIP: It often pays to search every index in these Gazettes, as an individual may appear in more than one.
And remember to search under aliases, they seem to be quite common!
Spades