Why it's so difficult to catch an active serial killer? Most of their murders can be masked as "natural cases". If the killers change their technique of killing every time, it will not be seen as a "series of crimes", they can operate for a long time.

If serial killers master their skills to dispose of the bodies of their victims, there is very little chance, that they will be found. Up to 40-42% of serial killers' crimes became "cold cases" for years.

That's why it's important to have the skills to recognise the killers if they are near you. A lot of serial killers have one similar trait, which you can notice.

The secrets of serial killers are described in this amazing crime book.

The book is written by a Forensic Psychiatrist and became very popular for readers across the world.