Dolgoe padenie - Deniz Maina

The story of one of the most gruesome - and strangest - serial killers of the 20th century. Even before his arrest, the press nicknamed him the "Beast of Birkenshaw." Peter Manuel was accused of killing at least seven people (probably there were many more). He was one of the last three criminals in Scotland executed by hanging.
... William Wott, accused of murdering his entire family, seeks to justify - and at the same time find out who actually did it. Only one person knows the truth. His name is Peter Manuel, and he said he knows where the gun from which shot Watt's wife, daughter and sister-in-law. But Peter Manuel is a liar.
And his lies can confuse anyone - even himself...