"The Hanging Tree -- Execution and the English people, 1770-1868" isn't really for the sensation-seeker or the ghoulish -- despite its rather lurid title (although, that said, its detailed descriptions of many of the condemned's last days could best be described as "unflinching"!).
Rather, it's a long and fairly academic review of capital law under the penal codes pertaining from the late 18th century until the abolition of public executions in the 19th.
My only criticisms of the book are that it is, at times, a little repetitive (although it would be hard to be otherwise, given that the book is 619 pages long); that it deals with rather few cases -- although these are gone into in great detail -- and that there are, at least to my way of thinking, a superfluity of bibliographical and academic references. Not a page can be turned without several! No matter, this is, at heart, more of an academic study than a populist one, so perhaps that is to be expected.
For me, its real interest lies in the commentary it presents upon the social mores and changing attitudes of the period and, for anyone interested in the history -- either social or political -- of the century covered, it goes a long way to explaining many underlying attitudes which might otherwise be almost incomprehensible to people today.
I think it's well worth reading.