Sam Melville played Kate Jackson's ex-husband in the series. He also played Glen Tucker in season two, episode twenty-two, "Murder Between Friends". In The Rookies (1972), the two had played a married couple.
The heart-shaped diamond necklace that Kate Jackson wore during most of the run of the series was purchased in 1979, just before she hosted Saturday Night Live (1975). She wanted something that would sparkle against the black silk blouse she wore that evening.