The Sniper's Wife is the 13th in Archer Mayor's Joe Gunther series, a police procedural series that I quite enjoy. It has dropped to $2.99 at Kindle and Kobo US.
Kindle US:
https://www.amazon.com/dp/B001N2ZWYI
Kobo US:
https://www.kobo.com/us/en/ebook/the-sniper-s-wife
ADD: And also
Chat, #18 in the series, for $2.99
Kindle US:
https://www.amazon.com/dp/B000WQ10W4
Kobo US:
https://www.kobo.com/us/en/ebook/chat-1