The right to counsel: criminal prosecution in 19th century London

We exploit a dataset of criminal trials in 19th century London to evaluate the impact of an accused's right to counsel on convictions. While lower-level crimes had an established history of professional representation prior to 1836, individuals accused of committing a felony did not, despite the prosecution being conducted by professional attorneys. The Prisoners' Counsel Act 1836 remedied this and first introduced the right to counsel in common law systems. Using a difference-in-differences estimation strategy, we identify the effect of the universal right to defence counsel. We find the surprising result that the professionalization of the courtroom led to an increase in the conviction rate. We argue that this effect was a consequence of the Act inducing a shift in the beliefs of jurors, who grew more likely to believe the evidence put before them once it could be challenged in an adversarial courtroom. We go further, and employ a topic modelling approach to the text of the transcripts to provide suggestive evidence on how the trials changed when the right to defence counsel was fully introduced, documenting a movement towards increased usage of precise and detailed language when discussing details of alleged offences.