''The Chief Witness'' is a classic Golden Age British mystery by Herbert Adams, originally published in 1940. It features the amateur detective and golf enthusiast Roger Bennion.

The story begins with a bizarre and macabre coincidence: two brothers—one a successful accountant and the other a prominent solicitor—appear to commit suicide at the exact same moment, despite living miles apart. In both cases, a timepiece is found broken to mark the time of death.

Roger Bennion, working alongside Inspector Goff, quickly deduces that the deaths were actually a double murder staged to look like a suicide pact. As the investigation unfolds, a nephew of one of the victims becomes the primary suspect, and Bennion must race to prove his innocence while navigating a web of fraud, hidden motives, and a high-profile murder trial.