I initially wanted Dahlén's first book, 'Nextopia', dealing with his field of expertise, namely consumer behaviour. As it turned was unavailable, I settled for this instead.
Murder off paper has never titillated my senses - Dahlén did! - and in point of fact I found the first part of 'Monster' lurid, prurient and rather shallow. The author accounts for his meetings around the world with famous killers, and not much is said that hasn't already been said before.
I had pretty much given up on Dahlén, when in the second part he started analysing, and it got a lot more stimulating!
As the researcher he is, he polls people and reaches the conclusion that our opinion of a person changes for the better when the person is said to be a murderer.
He examines the business around famous murderers (murderabilia) as well as the significance of murder in the entertainment industry. Murder is a cheap and simple way to instil suspense in a film / book / whatever.
He also questions how this permanent exposure to murder affects our behaviour. (Can the high murder frequency in the US be mere coincidence?)
Interesting, therefore! Well-written, too.
I will make another attempt at 'Nextopia' next time I'm in Sweden.