Nick Marsh is a British forensic photographer and his work could make the difference between a conviction and an acquittal. That’s why he must approach a crime scene with the shrewd mindset of a criminal investigator, the practical know-how of a forensic scientist and the integrity of a careful, honest photojournalist. A straightforward portrait of a distinctive line of work, David Beazley’s film is also a compelling argument for the value of experts in the age of the amateur.