Wallace was sentenced to 80 hours community work and was placed on six months supervision and had to pay reparation of $250 for the damage.
In response to Wallace's sentence, group manager community facilities and programmes at Hastings District Council, Alison Banks said safety was a priority at the library.
"Staff and public safety is paramount and in particular ensuring staff are trained and supported in their place of work is a key goal. It is important to remember, however, that libraries are inclusive spaces and open to all members of the community."
Keepa is due to reappear in the Hastings District Court on June 26.