Mystery killers with black gloves seem to appear everywhere from Deep Red to A Shot in the Dark, but tracing the roots of the Giallo body-count mystery genre seems to point to Mario Bava's Blood and Black Lace (AKA Six Women for the Murderer). It certainly brings a particular level of style to the proceedings with its 1960s colour scheme being mixed with plenty of dark shadows and sinister lighting. So let's put on the leather and get into this.
There's a whole lot of neon lighting here, and in general this is a visual movie first with the whodunnit elements being less important than how the deaths come about and how they are filmed. Set in a fashion house there's no excuse not to focus on this of course, with lots of swooping camera movements showing off the outfits as well as a lot of eerie mannequins. I don't think they are usually bright red like this, and in the whole place none of them are actually being used to display any clothes. There's a great intro sequence using all of these elements as each cast member is shown standing mysteriously next to props like this. It's hard to image why at the time it was replaced for English speaking audiences, but studio suits saw it necessary to use something more shocking.
Of course that's not to say the intrigue levels are not properly ramped up, and there are plenty of reveals with the models taking drugs and having affairs, while other characters are involved in blackmail and various questionable activities. What a scandal! With everyone acting so suspiciously it adds a lot of mystery as you'd expect and things quickly get complicated as the body count rises and the red herrings come and go. One major element is the discovery of a dead girl's diary which soon gets the attention of most of the cast when it threatens to reveal their secrets to the police. You still get all the usual arrests and line up scenes although they wanted to veer away from the usual detective procedural elements.
While the period design aesthetic definitely adds to the experience, the same can't be said of the soundtrack. The jazz drum beats do at times lend it a certain amount of personality but in other moments it's pretty distracting. Luckily this is a minor point and the rest of it holds up rather than feeling dated. It's been mentioned elsewhere that this has influenced many later directors, and it's easy to see why. So many elements are striking from the fashion house interior to the faceless killer's outfit. While it's a film noted for it's amount of sex and violence it seems tame by modern standards, or even in comparison to horror from the decades immediately following this. The fashion models aren't dressed that thinly and the kills aren't really that shocking. But it's not always about the amount of gushing blood, and for a good mix of atmosphere and murder mystery thrills it's a great example of this kind of story; even if the final motives feel a bit like an afterthought.