One of the few times Lawrence Tierney played a good guy. He also was the hero in Step By Step; in both, he's the Wrong Man aka falsely accused of murder: having to prove his innocence to, by the end, find the real killer. He was also the hero in Bodyguard, the last movie he did before being fired by RKO. Ironically, he was on pretty good behavior on that set (but was fired for his past arrests); however, co-star Priscilla Lane also complained that Tierney could be difficult.
Lawrence Tierney worked on this movie after being fired from RKO for being arrested multiple times for drinking and fighting. He was trying to prove himself to other studios, but could only get a low-budget production filming in Portugal because no one would hire him in America. After the movie wrapped, he got a good report on his behavior on set (and got the heavy role in the film noir Shakedown). However, ingenue Marissa O'Brien (aunt of Margaret O'Brien) did state, a few months later, that Tierney could have been better than he was.
An early movie about the deadly fish, piranha. In English, the singular "Piranha" could refer to one or a thousand. In this movie, with some characters playing Portugal locals with Broken English, they... along with the American actors... pronounce Piranha as "Pir-awn-yahs".