A Little Local Murder is an early (1970s) non-series title by Robert Barnard - apparently early enough that it's eligible to be a "Pan Heritage Classic" title, whatever that means...
It has dropped to £0.99 at Kindle UK. It was previously on sale in the US, so if you travel, check carefully before you buy!
Kindle UK:
https://www.amazon.co.uk/dp/B00AER805G
Kindle UK/Smile:
https://smile.amazon.co.uk/dp/B00AER805G