The thin blue line

John Sutherland joined the Met in 1992, and rose quickly, through the ranks, to become a senior police officer. But in 2013, he suffered a major mental breakdown, and his career was effectively over. Since then, he has written a book on his experiences, Blue: Keeping the peace and falling to pieces, which became a Sunday Times bestseller and was reviewed in the last issue of Sorted. His second book, Crossing The Line will be out in May 2020.

Why did you decide to become a policeman?

I was about 16 when I decided that I wanted to become a police officer. Looking back now, I suppose that I was looking for adventure – wanting to be part of something that matters. If you were to ask most police officers why they joined, they would tell you, simply, they wanted to make a difference. That sounds about right to me.

You were a successful police officer. What made you successful, and why do others struggle?

It would be for others to say whether I was successful, but I certainly love...