His Burial Too (The C. D. Sloan Mysteries)

In this crime novel by CWA Diamond Dagger winner Catherine Aird, Detective Inspector C. D. Sloan returns to solve a locked-room mystery, but he’s thrown for a loop when a prominent industrialist turns up dead

On the hottest day in living memory, Richard Mallory Tindall, the owner of a patent firm, does not return home to Cleete village. When a man is found crushed to death, Tindall’s case goes from missing person to homicide.
 
In the course of solving murder cases, Detective Inspector C. D. Sloan has seen all manner of ugly death. But there’s something particularly gruesome about this one, the body crushed beneath the marble and iron of an old Saxon church tower. With rubble blocking off access to the crime scene, no one can get close enough to inspect the body. What little evidence is available—a burned match, a black thread, an earring—doesn’t bode well for a quick and easy solution.
 
Even the legendarily cool-headed great detective might begin to crack when a second body turns up. And then an important file goes missing from Sloan’s office. How does it all connect?