You are in luck, my friend, because I have spent my entire academic career investigating crime in this era. The first place you need to start is the Old Bailey Online. This has pretty much every bit of extant data held in the records of the Old Bailey, which is London's court. You can search by crime, keywords, year, sentences, etc. And lest you think that this isn't a viable academic source, it is. The information pages, articles, etc., are all written by well-respected academics. The University of Sheffield provides the backing for the project. I cited it for my PhD thesis and I've seen others who've done the same.

Now, the Old Bailey Online has a great annotated bibliography, but I'll tell you which authors I think you ought to start with: JM Beattie, Peter King, Clive Emsley, Douglas Hay, and Peter Linebaugh. Beattie is also a really great dude who is happy to help. Douglas Hay is a very good Marxist historian who backs his research with exceptional statistics that you could use, though I don't agree with his conclusions.

• Beattie, J. M. Crime and the Courts in England 1660-1800. Princeton, 1986.
• Beattie, J. M. Policing and Punishment in London, 1660-1750: Urban Crime and the Limits of Terror. Oxford, 2001.
• Chadwick, Roger. Bureaucratic mercy : the Home Office and the treatment of capital cases in Victorian Britain. Garland: New York, 1992.
• Gatrell, V. A. C. The Hanging Tree: Execution and the English People 1770-1868. Oxford, 1994.
• King, Peter. Crime, Justice and Discretion in England, 1740-1820. Oxford, 2000.
• Linebaugh, Peter. The London Hanged: Crime and Civil Society in the Eighteenth Century. Allen Laine Press, 1991.
• Sharpe, J. A. Judicial Punishment in England. London, 1990.

Meta-data regarding capital punishment in England

Like, a number for how many papers have been published on the topic or something?