As a recent fraud case proved, expert witnesses can cause great trouble. In the middle of the 19th century, degrees were sold more or less over the counter by seemingly respectable universities such as Germany’s Heidelberg, while Dr Thomas Smethurst, accused in 1859 of murdering his mistress, purchased his from Erlangen.

It was in the Smethurst case that the expert for the Crown, Dr Alfred Swaine Taylor, blundered. Married in 1828 to a woman 20 years his senior, after 30 years together Smethurst took up with Isabella Bankes, bigamously marrying her in the pious hope they would marry on his real wife’s death.

But four months after her ‘marriage’ Bankes became ill and died two months later. As the sole beneficiary, suspicion fell on Smethurst. He was charged with murder on the basis of the evidence of Dr Taylor, who in 1844 had published what would become the standard textbook A Manual of Medical Jurisprudence.

At the inquest into Bankes’ death Taylor said he analysed the contents of medicine bottles found in Smethurst’s rooms and in bottle 21 he had found arsenic. Taylor conducted further tests and at the trial accepted he had used impure equipment and retracted his evidence. The damage, however, had been done. With a flawed defence coupled with a biased summing-up against him, Smethurst was convicted. After both the conviction and Taylor were attacked in the press, the home secretary appointed the ‘best known surgeon in London’, Sir Benjamin Collins Brodie, to adjudicate. He said ‘there is not absolute and complete evidence’ of Smethurst’s guilt. Smethurst was pardoned but received a year for bigamy.

It was not until the Medical Act 1858 that the General Medical Council was established, providing a standardisation of medical qualifications. Even then the act was not retrospective, so holders of diplomas from continental medical schools who would never have qualified under the new examination system could continue to appear as expert witnesses for the rest of their lives.


James Morton is a writer and former criminal defence solicitor