Chris Gregg rose from bobby on the beat to become Detective Chief Superintendent and head of the Homicide and Major Enquiry Team of West Yorkshire Police, the sixth largest force in the UK. During a 34 year career his cases included those of the Yorkshire Ripper; 'sexual sadist' and murderer of schoolgirl Leanne Tiernan, John Taylor; cop-killer David Bieber; 'Angel of Death' Colin Norris; and the UK's most prolific murderer, Dr Harold Shipman. He also brought to justice John Humble, the infamous Ripper Hoaxer responsible for delaying the real Ripper's capture by two years.

Dr Angela Gallop began her career as a biologist at the government's Forensic Science Service before going on to form her own company and become the UK's most celebrated forensic scientist. Angela's findings helped solve the murders of young London mother Rachel Nickell, 'God's banker' Roberto Calvi, Lynette White, Gareth Williams and south London school boys Damilola Taylor and Stephen Lawrence, as well as the so-called 'Pembrokeshire' murders (as seen on TV). Angela met Chris Gregg working on the investigation of Yorkshire Ripper victim Helen Rytka. Together in 2010 they created Axiom International to offer forensic expertise and training to agencies all over the world.