"Old Sparky" by Anthony Galvin offers a well-researched and informative look at capital punishment throughout history. It starts off strong but the later parts of the book may feel a bit repetitive with its listing of case descriptions. There's also perhaps too much focus on just electrocution. The final chapters provide reasonably good analysis of the problems with execution as a form of punishment but he seemed to dismiss methods similar to those used in euthanasia as a possible way to at least avoid the executions being a form of torture on shaky grounds and only mentions it in passing.

The book isn't for everyone but for those interested in true crime and the history of capital punishment, "Old Sparky" can be worth going through. While it may not be the most engaging or entertaining piece of nonfiction, it provides a solid overview of its subject matter.