Killing Time by Thomas Berger [TRADE PAPERBACK / 1981]
VINTAGE TRADE PAPERBACK  DELTA
Awesome copy with some light wear to cover and sticker on spine. Pages are still white and unmarked.
The novel opens as Arthur and Betty Bayson, arriving at her mother's home for their annual Christmas Eve dinner, stumble on the murdered bodies of Betty's mother and sister, as well as that of the household's current boarder.