The law was rigid as well as limited and often flawed in the late 19th century in England. Judicial proceedings were often swayed by social status and wealth. In reaction to rising crime associated with rapid urbanization and industrialization, the Metropolitan Police was established in 1829 with extremely wide powers, especially concerning petty crime. Policing procedures were not always fair or transparent, and Conan Doyle intervened in two cases of wrongful imprisonment. Conditions in prisons were often inhumane, including sensory deprivation, often leading to suicide.

Sherlock Holmes epitomizes a new type of justice that does not necessarily align with the law. The detective values his own opinion and judgment above that of the police or the court and prefers not to involve the authorities unless they are directly connected to a case, or if he requires help in capturing a dangerous criminal. In the blue carbuncle case, for example, Holmes makes his own decision about the culprit’s fate based on his knowledge of human nature and the effect prison has on people. Furthermore, cases that are not strictly illegal, such as Mary Sutherland’s situation, would not normally be handled by the police. Holmes’s role is to step into the gap between the legal system and the need for justice.