In the arena of improperly obtained evidence the Irish courts have, for some time, operated one of the strictest, if not the strictest, exclusionary rules in the common law world where evidence is obtained in breach of constitutional rights. Through an interesting and intricate series of cases beginning in the mid-1960s with People (AG) v O’Brien [1965] IR 142 on to People (DPP) v Kenny [1990] 2 IR 110, and beyond, the legal basis for exclusion was established, considered and reconsidered. This case-note discusses the High Court and Supreme Court decisions in the latest in the line of such cases, DPP (Walsh) v Cash [2007] IEHC 108 (28 March 2007), [2010] IESC 1 (18 January 2010) and considers its impact on suspect rights and policing in the Irish pre-trial process.