Book excerpt: The "Inside-Out", or presumptive, approach to the investigation of firearm crime presumes that there is an abundance of data inside which is transferred to fired bullets and cartridge cases and outside every crime gun. When fully exploited, this data can be used to generate actionable information of tactical and strategic crime solving value. This book describes, in detail, the 13 critical tasks needed to balance people, processes and technology in order to solve more gun crime.