The Reason It Doesn't Work

First of all, the original was based on a real person - a German named Peter Kürten - and the case was still fresh when the the 1931 version was made. More importantly, however, the story reflected the post-WWI horrific state of the Weimer Republic...and was a metaphorical comment on the times. Third, the 1951 rip-off kept referring to the situation as "baby" killings (as is common when the media tries to overly-sensationalize occurences with kids, as if claiming that they're "babies" somehow makes the situation more psychotic, hideous, and emotional) when, in fact, the killings were older children with whom the killer could have short-term "relationships" before he killed them (which further exemplfied his psyche).