Just two quick suggestions on the occasion of the solstice and in the tradition of old tales best for winter:
From the Washington Post, “Fed up with that Hallmark good cheer? Escape with a classic mystery” by Michael Derida. Great suggestions for classic murder mysteries. You can download some of these for free on the Gutenberg Project.
And while not murder mysteries per se (though people do die mysteriously), my recent discovery of the BBC’s A Ghost Story for Christmas, part of the British tradition of telling supernatural tales at Christmas. The series started in 1971 and has continued off and on until today. They include adaptations of classic stories (that you can also find on Gutenberg). I have watched the first several, starting with four errie tales by M. R. James. These were filmed in a hand-held camera manner that served perfectly the haunting, and they tend to linger in the mind. You can find these on Britbox and on the Internet including YouTube (such as the first bunch here).