Along with Sheriff Blubs, Durland is the main law enforcement in Gravity Falls. However, he doesn't do a very good job- he is illiterate, easily distracted, and in general not very bright. He often has loud outbursts, and screams in stressful situations.
Sheriff Blubs is not only his colleauge, but also his best friend. Together, they tend to get lazy and slack off from their job to do other activities.