Police say that three court services officers took action when a man pulled out a knife at the security check-in at police headquarters.
Just before 1 p.m., police say a man walked in through the main entrance, put a bag down at the security check-in, and pulled out a knife.
He then allegedly said he was there to kill officers.
One of the court services officers pulled out his baton, another got the 25 civilians inside headquarters into the gift shop for safety, the third ran to get armed officers.
Police officers arrested the man at gun point, and he surrendered peacefully.
Investigators are looking into whether mental health is a factor. No one was injured.
With files from Hayley Cooper