Victorian Crime - This site is by the British Library. It has many period illustrations.
The Ratcliff Highway Murders - 1811. Sensational murder case which attracted much public interest through the publication of newspapers and penny dreadfuls. The Maul and the Pear Tree by T. A. Critchley and mystery novelist P. D. James is a critical study of these crimes.
The Proceedings of Old Bailey London - Proceedings of trials from 1674 - 1913. This is a work in progress and not all years have been entered yet. There is background information about this period and a section for teachers who wish to use it with their classes.
Villainy Detected - "The materials on this site illustrate eighteenth and nineteenth century crime and punishment practices in America and Britain." This site has informative essays and links to relevant sites. It is by Lehigh University.
Victorian Web - Extensive source of information on Victorian England.
Dying Speeches and Bloody Murder - Crime broadsides collected by the Harvard University Law Library. These are penny papers published in the 1800's describing crimes and executions.
The Word on the Street - Broadsides from the National Library of Scotland covering the period between 1650 and 1910. You will find quite a few about crime and bodysnatching.
Early Eighteenth-Century Newspaper Reports - A compilation by Richard Norton. In addition to the crime reports, there are reports of other aspects of life in England in this time period.
Papers Past- A digitised collection of New Zealand newspapers from 1840 to 1915. This collection may be searched for any crime of interest to you.
Dime Novels Full Text - Popular reading from 1860 to 1920. These were an inexpensive way to read crime stories. This site is by Stanford University.
Why We All Love a Victorian Murder - "Sexual repression, dark alleys, great detectives, ornate prose. No wonder the 19th century is our template for crime fiction". This is an article by James McCreet in The Guardian, May 15, 2011.
Mapping Emotions in Victorian London - A crowdsourced project to relate locations in London to Victorian fiction. The mystery reader will probably be most attracted to the areas of "Dreadful London".
Classic Crime Fiction - Author biographies and bibliographies, articles on the history of the mystery novel, and book cover illustrations. This site is well worth a visit.
Det.Novel - A history of the detective novel. This site is by William Marling.
The Mystery File - This site has book reviews, author interviews, and mystery readinglists. There are also articles on older mystery novels, mystery series, and TV mystery characters.
The Golden Age of Detection Wiki - Information about authors and books, but since this is a wiki, the reader should question the reliability of the information.