A 17-year-old boy, who was volunteering as a firefighter in Sydney's west, was arrested on October 2 by the NSW Police Arson Squad.

It comes after a pattern of allegedly deliberately lit bushfires puzzled police until the investigation turned toward the teenage volunteer firefighter who extinguished them.

Police allege that a series of bushfires in the greater Wallacia area between June 23 and September 7 were sparked intentionally by the teenager.

The 17-year-old from Warrimoo responded to each bushfire in his role as a volunteer firefighter, police alleged.

He was taken to Springwood Police Station, where he was charged with three counts of intentionally causing fire and recklessly spreading the blaze.

He was also charged with two counts of false representation, resulting in a pol

See Full Page