This unsolved cold case sounds a lot like something that would happen in Hitman.
Basically the guy was lured into his hotel room alone and someone garroted him, tried to hide his body in the trash compactor but ended up hiding him behind a door near the stairs. It has never been solved but clearly was a professional hit.
If I remember correctly, it was discussed at some point in the past, but did we come to a conclusion where Dartmoor/the Manor is, or what it was based on?