Complex sentence: He came armed with a Smith & Wesson Model 10 police revolver (New Zealand police in 1990 didn't usually carry firearms) and enlisted the help of Constable Russell Anderson, who had arrived a short time earlier with the fire service.
Split into simpler sentences: He came armed with a Smith & Wesson Model 10 police revolver. Guthrie enlisted the help of Constable Russell Anderson, who had arrived a short time earlier with the fire service.