Millions of historical criminal records from England and Wales are going online.
Half a million of the records from 1770 to 1934 have been published today by the genealogy website findmypast.co.uk in association with The National Archives .
They can now be accessed by anybody, anywhere in the world - although there will be a small fee to do so.
A further two million records will be going online by the end of the year.
Among the documents are court papers, verdicts, sentences and mugshots.
Many of the photographs show suspects holding their hands to their chests, in case they have an identifying feature like a missing finger.
Family historian Amy Sell told Sky News: "You may get their age or a description of what they looked like.
"You may even get a photograph as well, which is amazing. Coming face to face with your ancestor is quite rare.
"You will also know what they were convicted of, what the crime was, and also what the punishment was."
Two-and-a-half-million documents are being painstakingly scanned by staff at The National Archives in Kew.
Those interested in tracing their family history can search the files by entering names and keywords.
But the documents also provide a fascinating insight into the criminal justice system at the time, and wider social history.
Records specialist Paul Carter says we do not have much detail about ordinary people's lives in the 18th and 19th centuries.
"What people should be looking for - as well as the murderer or the thief - is the rural poacher, or the early trade unionist at a time when trade unions were illegal," he said.
"You'll get Chartists in here and people who were trying to reform the way society worked. So you are going to get an awful lot of very different people who come through the system, for different reasons."
You can also look up the criminal records for more well-known names like the political activist Emmeline Pankhurst and author Oscar Wilde.