Officers first spotted a stolen black GMC Sierra early Saturday morning and when they tried to pull it over, the driver refused to stop.
The air support unit followed the truck to the intersection of 22nd Street and 2nd Avenue where it crashed into a Nissan Frontier.
The GMC driver then allegedly pulled what appeared to be a firearm on the Nissan driver and took off in that truck, eventually abandoning that truck in the 1300-block of 8th Street East.
At that point police said he tried to steal another vehicle.
He ended up crashing a Dodge Ram into a building and was arrested.
A search turned up a pellet gun.
The 27-year-old man is facing 12 charges including armed robbery, possession of stolen property and possession of a weapon dangerous to the public.
He is scheduled to appear Monday in Saskatoon provincial court.