Clare Mackintosh saw off the challenge of some of the world`s best-known writers to land the title of the Theakstons Old Peculier Crime Novel of the Year Award. 

Harry Potter author Rowling was shortlisted for Career Of Evil, written under her pen name Robert Galbraith, but lost out to the ex-Thames Valley Police inspector and her debut book, I Let You Go. 

Mrs Mackintosh, who spent 12 years with Thames Valley Police (TVP) before becoming a full-time writer, found herself in elated literary company on Thursday night (July 21) at the opening night of the Theakston Old Peculier Crime Writing Festival in Harrogate. 

The crime writing prize`s previous winners include Val McDermid, Lee Child, Mark Billingham, Sarah Hilary and Denise Mina. 

And a special presentation for her outstanding contribution to crime fiction was made to Ms McDermid — the winner of the seventh Theakston Old Peculier Outstanding Contribution to Crime Fiction Award. Ms McDermid joins renowned authors Lynda La Plante, Ruth Rendell, Sara Paretsky, PD James, Colin Dexter and Reginald Hill as recipients of that prize. 

Mrs Mackintosh, a mother of two sets of twins, beat off competition from a shortlist of six British and Irish authors whose novels were published in paperback between May 1, 2015 and April 30 this year. 

As well as JK Rowling’s novel, the other shortlisted titles were Rain Dogs by Adrian McKinty (Serpent’s Tail), Time Of Death by Mark Billingham (Sphere), Tell No Tales by Eva Dolan (Harvill Secker) and Disclaimer by Renee Knight (Black Swan). 

The former officer, who was presented with the award by title sponsor Simon Theakston and broadcaster Mark Lawson, collected a £3,000 cash prize, as well as a handmade, engraved oak beer cask — carved by one of Britain`s last coopers.  

Accepting the award, she thanked her publishers and agent for their support and the “crime-writing community for their endless encouragement”. 

Mrs Mackintosh`s I Let You Go was a Sunday Times top ten bestseller for 12 weeks, and was the fastest selling title by a new crime writer in 2015. 

It was selected for both the Richard and Judy Book Club and ITV’s Loose Women’s ‘Loose Books’, and has been translated into almost 30 languages. — selling more than half a million copies to date. 

The inspiration for her debut novel success has been influenced by the memories of two tragedies, one very personal. 

And the storyline of her book, which begins when a five-year-old boy is killed in what appears to be a hit-and-run accident on a rainy night in Bristol, seems to be inextricably linked to events in the novelist`s life. 

As a Surrey University graduate she had what she describes as a “sort of an epiphany” after watching a careers film on the police — and deciding to join TVP as soon as she had graduated in 1999. 

That same year, the first tragedy struck when a car hit a child in Oxford. She recalls: “The driver was never caught, despite lots and lots of community intelligence and huge efforts by the police.  

“There were so many people talking about who had done it, but no one was prepared to give evidence; people were arrested but not charged. 

“During the 12 years I was in the police, it never really went away.” 

Despite everyone knowing the name of the person suspected of being the driver, nothing happened.&n