Received: 23 October 2002 Accepted: 17 February 2003 Published online: 9 April 2003 © Springer-Verlag 2003 Abstract An Australian case study is presented in which defendants convicted of manufacturing a drug of abuse were acquitted on appeal because of shortcomings in the prosecution’s case that established the identity of the material seized. The need to have proper standard operating procedures that can be followed routinely and correctly is highlighted. Education is needed for forensic analysts and the legal profession to try and produce systems in which the proper outcome is achieved. Keywords Forensic science · Courts · Uncertainty · Accreditation Accred Qual Assur (2003) 8:179–183 DOI 10.1007/s00769-003-0609-9 GENERAL PAPER D. Brynn Hibbert Scientist vs the law A recent judgment in the Court of Criminal Appeal of New South Wales highlights a problem faced by courts and scientists [1]. Australia has an adversarial system of justice that is derived from the English system. In each case, a plaintiff has to persuade the court of his or her case, while the defendant argues the opposite. The end of the case is when the Court, a judge acting as a jury, or a jury of ordinary men and women, determine for or against the plaintiff’s case. The case in hand is the trial of Regina (the Queen) v three gentlemen who were found guilty of ‘knowingly taking part in the manufac- ture of not less than the commercial quantity of a prohib- ited drug, namely methcathinone.’ On appeal, the con- victions were overturned on the grounds that the jury did not take sufficient account of the shortcomings of the Crown’s evidence of identity of the alleged drug. In the local press, much was made of the suggestion that they were really trying to make the male anti-impo- tence drug ‘Viagra’ (sildenafil)! If this were indeed a se- rious defence it is difficult to see how a synthetic chem- ist might have decided to make structure (1) via structure (2) (Fig. 1). In this paper the analytical chemistry of the case is explained, and broader issues are discussed that relate to matters relevant to accreditation and quality assurance. The nature of expert opinion in the Australian system is also presented. D. B. Hibbert ( ✉ ) School of Chemical Sciences, University of New South Wales, 2052 Sydney, NSW, Australia e-mail: b.hibbert@unsw.edu au Fig. 1 Structures of 1-[[3-(6,7-dihydro-1-methyl-7-oxo-3-propyl- 1H-pyrazolo [4,3-d]pyrimidin-5-yl)-4-ethoxyphenyl] sulfonyl]-4- methylpiperazine monocitrate (Sildenafil marketed as Viagra) and (2) methcathinone