Rennie joined Hawkins in May 2009 after a career with Essex Police spanning 33 years. He was involved in a wide variety of criminal investigations including arson, burglary, fraud, rape and homicide. During the last six years of his service he was a Crime Scene Investigator where he specialised in fire and arson investigation. He was awarded the Crime Scene Photographer of the Year in 2009. Rennie attended the Advanced Origin & Cause/Courtroom Techniques, at the Federal Law Enforcement Training Centre in Georgia, USA (Bureau of Alcohol, Tobacco, Firearms and Explosives) in 2004. He is a member of the International Association of Arson Investigators (IAAI) and has delivered training in forensic and arson investigation to the Police and Fire Brigades throughout the UK. Rennie specialises in the investigation of fires in domestic and commercial premises, as well as damage and break-ins. Rennie is an Associate based in the Cambridge office.