We've mentioned, in our "Character Analysis" of Inspector Lestrade, that the policeman makes a good foil for Sherlock Holmes because he works inside the law while Holmes is a free agent. Holmes gets to choose whom he lets go and whom he carts off to the court system. But if law isn't necessarily one of Holmes's primary means for keeping criminals in line, threat to reputation is. The importance of reputation in Conan Doyle's representation of Anglo culture is pretty evident. Probably the best example of this is Neville St. Clair, who is willing to go to prison disguised as Hugh Boone under the charge of murdering Neville St. Clair rather than confess to everyone that he has been posing as a beggar all these years.
Other examples include James Ryder ("Blue Carbuncle"), who begs Holmes to release him to save his mother and father shame. Jabez Wilson goes to Holmes out of outraged pride at being tricked by the Red-Headed League, and Alexander Holder ("Beryl Coronet"), the King of Bohemia, and Lord St. Simon ("Noble Bachelor") all hire Holmes to preserve their reputations. In other words, reputation is a great plot motivator throughout these stories, both as a reason for clients to find Holmes and as a way for Holmes to keep wrongdoers in line without having to send them to the criminal justice system.
Conan Doyle largely steers clear of discussion about women's reputations because he continues to promote the "Angel in the House" ideal of domestic womanhood, which requires women to be above reproach.
Instead of turning to the law courts, Holmes uses threats to criminals' public reputations to keep them from repeating their offenses.