Environmental Health Professionals (EHPs) and the law: sources of law and principles of operation; EHPs, attitude and the law; civil liability. Entry: powers of entry, summarized for various statutes encountered; notice of entry; warrants; force; obstruction. Principles of investigation: documentary evidence and memory refreshing; notebooks; inspection records; photographs; PACE, cautioning, interviews; statements; reports. Enforcement: policy formulation, offence and offender aggravation and mitigation, the scale of offence; discretion; statutory notices, the technique of drafting, service etc.; formal cautioning; prosecution. Criminal proceedings: information, complaint, summons; EH professionals as prosecutors; strict liability and the burden of proof. Court procedure: personnel of the court; layout of the court; giving evidence; expert witness; costs and compensation.