York Castle Prison in the UK recently released a database of people who were prisoners there. The database is not comprehensive — it focuses mainly on the 18th century — but information available for each inmate is extensive. The records are at http://www.yorkcastleprison.org.uk/family-history.html. In addition to the prisoner records, the site also includes information on insolvent debtors (mostly from the 18th century) and executions.
The site wants to emphasize this, so I guess I will too — the database is based on original records but the York Castle Prison does not hold any original records, and record images are not available.
The search page of this site suggests that you can search by name or crime, but you can also search by keyword. (If you do search for names, be sure to try several different iterations, as consistent spelling is definitely not the case for these records.) I did a search for innkeeper. Search results are divided into three sections: Executed, Transported (for convict labor), and Debtors. (In this case there were three executed, one transported, and almost three dozen debtors.) The results are listed underneath each tab, with a name, date, and details about the crime/person. Amount of detail seems to vary a lot; you may get that someone was hanged for horse stealing or you might get details about their crimes and even what other family members had been convicted of doing.
As I noted to start with, the prison does not have the original records. Each entry however has some source details, with cryptic notations. Be sure to download the York Prison Factsheet (PDF) for information both on the databases available and the sources used to create the databases. Alas, much of the source data is unavailable online.