|You can use The National Archives (UK) - Petitions for mercy, 1784-1830 anywhere. You don't need a Library card.|
In Advanced search, enter the name of the convict (or petitioner), court or place in the 'exact word or phrase' box under Keyword options and add reference number HO47 under Search within. Click Search.
Click the relevant result to view a summary of what information is in the folio such as the crime, sentence and grounds for clemency. It will also give you the catalogue reference, e.g. HO47/37/31. You can purchase a copy of the record if it is not available online.
Bevan, A 2006, Tracing your ancestors in the National Archives, 7th edn, National Archives, Richmond.
While many crimes were capital offences not all received a death sentence. Many convicts pleaded for mercy and were pardoned on the condition of transportation to Australia.
Petitions for mercy can be found in various collections within The National Archives (UK).
One collection that is being progressively indexed online is Judges reports on Criminals, 1784 to 1830: Home Office (HO47).