Ray Stricklyn noted in his autobiography "Angels & Demons" that co-star Norma Eberhardt had one blue eye and one brown eye. If you look carefully at a few of her close-ups, even in this black-and-white film, you can notice the difference.
Francis Lederer mentioned in a 1993 interview with Skip E. Lowe that he hated making this film and his agent had tricked him into doing it.
The British Hammer classic Horror of Dracula (1958) was released the same year as this low budget black and white feature, making this film quickly forgotten in the wake of Christopher Lee's successful portrayal in vivid color.
It's interesting that Gerald Fried, who previously scored Stanley Kubrick Paths of Glory (1957), did the score for this film and used "Dies Irae" throughout it, which later was used as the theme in Kubrick's The Shining (1980).