The worst offence a writer can perform is to be dull or boring. It is a very woeful offence to be boring. The reader will stop reading and move on to another book while keeping in mind the author is not to be seen again. If a crime novel becomes boring, there’s a very high chance it is because the writer was fatigued while composing the words. The worst bit of guidance I have ever been told, and it’s slung around like a rule that must be followed is; ‘Write what you know.’ It’s not entirely honest, as you should ‘Write what excites you.’ With research into what is exciting to you, so you then understand what you write, and that excitement will come across on the page and excite the reader.