The National Library of Medicine has put online a selection of murder pamphlets from the late 1600s to the late 1800s online. The murder pamphlets in the NLM's collection address cases connected to forensic medicine, especially cases in which doctors were accused of committing-or were the victims of-murder. You can see the NLM broadsides here.
And Harvard Law School has contemporary broadsides about sensational London crimes and executions primarily during the period 1820-1840 which you can see here. There’s a chilling account of a man who was executed in 1819 for an “unnatural offense” (being gay).