A Kamloops judge has ruled that a repeat offender with more than 70 criminal convictions deserves long-term offender status.

B.C. Supreme Court Justice Randall Wong announced the decision Wednesday in sentencing David Glen Hurst for setting a fire behind the Kamloops courthouse in 2009, the latest in a string of arsons stretching back at least 20 years.

Hurst, 52, has set fires from the Lower Mainland to the Southern Interior and was once known as Vancouver's "West End Firebug."

In the 1990s, Vancouver police believed he was responsible for 40 or more arsons involving buildings and vehicles, but authorities could convict him for only six of them.

The insurance claims from the fires totalled more than $900,000.

The 2009 grassfire Hurst lit in Kamloops quickly spread towards a nearby subdivision, and came within 80 metres of some homes, the court was told.

Wong noted in his ruling that Hurst has the mental age of an eight to 11-year-old and has limited insight into the potential consequences of his criminal acts.

He sentenced Hurst to seven years in jail and placed him under supervision for another 10 years, meaning he will be 69 years old before his supervision ends.

The long-term offender designation is less restrictive than dangerous-offender status, in which an individual can be kept in prison indefinitely.

With files from the CBC's Jackie Sharkey