This book covers hundreds of years of crime and vice in London, but is poor on detail. In almost every case in this book on which this reviewer knows something, errors of fact and judgement abound.
For instance, the author states Martha Tabram was 35 on death and that Mary Jane Kelly was married. Martha Tabram was 39; and I know of no evidence to suggest Kelly was married. The author states that Melville McNaghten was a Ripper expert, yet he joined the police after the killings had ceased. In any case, Sir MM said there were five murders only and here, the author claims there were six. The author thinks Druitt was born in 1840 - his birth certificate says 1857. Because the latter was a doctor's son and may have studied medicine, he was the Ripper, but we have no evidence to say he did study medicine - in fact, on leaving Oxford, he became a schoolmaster very soon after, as well as being a barrister. If the fact his father was a doctor is proof he was the Ripper, then this is very weak indeed, and in fact, no proof whatsoever.
Marlowe was with three other men in Deptford according to the inquest on his death, not two as stated here.
Whether Christie killed Mrs Evans is highly debated, but here it is passed off as fact.
Amelia Jeffs was not killed in West Ham Park, but in a house nearby. The other missing girls vanished earlier that decade, not in 1890 as suggested here.
The author refers to a murdered blackmailer - but the man died peacefully in bed.
There is the statement that Edmund Pook killed Jane Clousen, but witnesses claim he was elsewhere at the time, so it seems impossible.
A little checking would have helped this book, relying as it does wholly on published sources and not straying far from the beaten track of the usual suspects.