A Parmelia man who smashed seven windows and wrote the word egomaniac on Premier Colin Barnett's electoral office has been fined $1500 and ordered to repay $4800 for the damage.
Adrian Thomas, 29, described the vandalism as a "violent outburst" in Perth Magistrates Court today.
The court heard Mr Thomas, who suffers from Aspergers syndrome, handed workers in Mr Barnett's office safety glasses before he smashed windows with a hammer.
He pleaded guilty to two counts of criminal damage.
Chief Magistrate Steven Heath denied Mr Thomas' application for a spent conviction on the grounds that the offender was fully aware of his actions and had premeditated the attack.
Outside court, Mr Thomas read out a statement. He apologised for his actions, which he said were driven by frustration at a long list of decisions made by the Premier.
Mr Thomas did not go into detail about which decisions angered him and would not answer questions from media. It is believed the attack was motivated by the Premier's shark capture policy.