I just watched 'Profondo Rosso' or 'Deep Red' to give it it's English title and it reminded me a lot of 'Blow Up', a film which I like a lot. A quick scout around the search engines yeilded a few articles that point to Argento essentially remaking or paying homage to the 'Blow Up' story as 'Deep Red'.
The alternative title of this double bill could be David Hemmings Investigates, in a similar vein to David Hemmings Happens, his 1967 album.
Argento's 'Blow Up' from BBC film pages, link.
Kinoeye article; 'The Principles of Association', link.
Earlier post on David Hemmings Happens, link.