Willful Murder (1981)

Original title: 日本の熱い日々 謀殺・下山事件

The president of the Japanese National Railways is found dead during a period in which train service is plagued by numerous layoffs, strikes and shutdowns. The government says that the president was murdered; the police claim it was a suicide. A quizzical reporter follows the case for years, but the basic question remains unanswered: was the victim killed by members of the burgeoning Communist movement in Japan, or was the death stage-managed by the authorities in hopes of discrediting the Communists?