Dr Walker will describe his chemico-legal practice in Northern Ireland and his work as Referee Analyst science managing technical appeals to the Government Chemist. There are many chemists involved in court work, including forensic scientists, public analysts and toxicologists. Few, though, have a mixed chemico-legal practice and Michael will describe the typical process from initial enquiry to trial illustrated with cases from his civil and criminal (mainly road traffic) practice. Michael will also discuss his work as referee analyst at the Laboratory of the Government Chemist, LGC. In the UK the Government Chemist provides a statutory route of technical appeal from the findings of Official Control Laboratories. Described informally as ‘referee analysis’, this can be triggered when labs disagree about results or their interpretation following official controls in the food and animal feed sectors.