Three Joffe murder mysteries are free right now. Of these three authors, I've read a few of Rebecca Tope's Thea Osborne/Cotswolds series, and liked them well enough, but haven't read any in this series.
A Dirty Death is the first in the Den Cooper/West Country series by Rebecca Tope.
Kindle US:
https://www.amazon.com/dp/B0B889TJ7P
Kindle UK:
https://www.amazon.co.uk/dp/B0B889TJ7P
Murder on Port Meadow is the first in the Oxford Dog Walker series by Annie Dalton, with Maria Dalton
Kindle US:
https://www.amazon.com/dp/B09VH5T656
Kindle UK:
https://www.amazon.co.uk/dp/B09VH5T656
Darkness Rises is the first in the Jeffrey Flint archaeological mystery series by Jason Monaghan. I got all excited when I read the words "archaeological mystery", since I tend to like mysteries with archaeological themes, but reading the blurb, I'm not so sure. Still, it's free, so I may try it sometime. And, of course, YMMV....
Kindle US:
https://www.amazon.com/dp/B00ZFPKCY4
Kindle UK:
https://www.amazon.co.uk/dp/B00ZFPKCY4