I had never heard of this story until I purchased a Samuel Clements (aka Mark Twain) book that contained it with two of the stories of his (Huckleberry Finn and Tom Sawyer) that I wanted to read (and it also contained the Prince and the Pauper). In a way this story is very similar, but very different, to Prince and the Pauper. The similarities involve two boys that take each other's place, but that is pretty much where the similarities end. This story is set in the United States and the two boys are switched at birth, not by accident, but deliberately. Further, the story only focuses on one of the boys, since the switch involved a pure white baby and a baby that was 1/32 part Negro, but because of that really minor part that was Negro, he was still considered a Negro.
The character whom the title is named after, David Wilson, really takes a back seat for most of the story, and only comes to the fore in the last few chapters when he is finally given the chance to prove his worth. Basically Pudd'nhead is a lawyer that moves out to a small town south of St Louis and on his first day makes a stupid comment and is then cursed with the name Pudd'nhead, which basically means stupid. Pudd'nhead is more eccentric than stupid, and one of the things that makes him eccentric, his collection of fingerprints, is what ends up turning him around and making him a hero.
Some have said that this story is a courtroom drama, but most of the comments that I have read about it have suggested that it is not. While there is a courtroom scene, it only makes up a small part of the story, though much of the story builds up to this scene. In a courtroom drama the murder is usually commented near the beginning, or even before the story begins. However the murder in this story does not occur until near the end, and while it is clear why the murder was committed (money and unpaid gambling debts) it is more like an anti-climax.
The thing that impressed me the most about this story though was that forensic fingerprinting played a very major role in an era before fingerprinting was actually accepted as evidence in court. However remember, this is a small town in rural America, and as such courtroom scenes become more like some sort of show (as is indicated in this book) than some really serious matter as one would expect in the city. Remember, everybody knows everybody else, including the judge, and it is basically the person that performs the best show that wins the trial.
However, that is still very much the case today. Trials are less to do with actually finding the truth and more to do with who tells the more believable story, and who the judge prefers to believe. In my time in personal injury litigation there are always stories about soft judges and hard judges. This is basically determined by who likes plaintiffs and who hates plaintiffs, and even then, their word is never final. When somebody else ends up paying the court fees, the ability of plaintiffs to actually prosecute their case increases.