In the Three Jolly Bargemen, Wopsle has in his hand a newspaper telling the story of a popular murder, which seems fairly unanimous in its popular verdict.
The Kent Tragedy in 1831 occurred near to Rochester, and seemed too to have a fairly unanimous verdict, though perhaps even Jaggers could have struck doubt into the minds of the prosecutors. In this case, in the end, John Any Bird Bell was convicted for the murder of Richard Taylor.

The Kent Tragedy 1831Dickens does not detail the story in his narrative, but murder stories were often sensationalised and popularised in print, as part of the culture of uncensored dissemination of real life cautionary tales to those who were tempted to break the law. The murderer's sentence, in the real life Kent story and in Wopsle's (if indeed he was convicted), would be death.
What is curious is that the story is further dramatised within the article in verse form - thirty lines of iambic heptameter to retell the story in a more theatrical way. Reading a similar piece in print, Wopsle would surely have relished this device as a chance to recount the drama to his companions.
Another example, from Enfield in 1832, is shown below, also with a verse retelling of the story of the trial and execution of William Johnson for the murder of Benjamin Danby.

The Enfield Murder 1832
Reproductions of Crime Broadsides: "The Kent Tragedy" (1831) and "Barbarous Murder at Enfield" (1832) courtesy of Historical & Special Collections, Harvard Law School Library.
Website: www.law.harvard.edu/library/special/index.html