A man who activated the sprinkler system at the Wanganui police station setting off the alarm and sparking a fire service callout was convicted in Whanganui District Court on Thursday.
Christopher Baird also carved "Chris was here 2014" into the police cell wall after he and a friend were arrested for stealing a pair of trackpants valued at $99.99 from Rebel Sport.
Baird faced one charge of theft and two of wilful damage for his actions on April 7.
Baird and his friend took the pants from the store and walked out without any attempt to pay for them, and were followed by staff.
Baird's friend then threw the pants at the staff members, said police prosecutor sergeant Rachel Willemsen.