The transportation is sometimes (although not always) by children, vulnerable people or others allegedly in debt who have been coerced by gangs. The ‘county line’ is the mobile phone link used for business, a choice of communication that is of course not linked to a specific fixed address, and may be used by many individuals.

Further, ‘cuckooing’ refers to the forceful practice of local people having their home of other assets, such as mobile phones, taken over and used by for the supply business.

The areas into which controlled drugs are moved experience increased levels of violence and weapons-related crimes as a result of this movement of what is widely perceived to be a valuable asset.

This book provides a useful guide to the context of this type of crime, and the many statutory authorities, with due regard also to the major related themes of human trafficking and exploitation.

There are chapters on county lines operations, offences that may emerge from investigations, potential defences available for victims of exploitation and the relevant sentencing principles.

The author identifies practical issues in county lines cases with the aim of assisting defence practitioners at every stage of proceedings, and relevant legal authorities are provided.

One thought arises from this book, and quite often, other law books. It is not stated anywhere, that can be found easily anyway, that the book is intended for court cases under English law.

County line managers have pushed into Scotland and no recognition is made of that cross-border trade. The law may differ in practice: one debt-ridden courier’s duress is another’s coercion. There is no mention either of Northern Ireland.

Nevertheless, there are several relevant statutes, considered in this book, that are common to the home jurisdictions to suggest that those interested in controlled drugs cases will find it of use.

A Practical Guide to County Lines, Human Trafficking and Exploitation by Gerwyn Wise. Published by Law Brief Publishing, 94pp, £49.99.