Neil C’s review published on Letterboxd :
This 1971 Spanish film, also known as 7 Murders for Scotland Yard is, I think, the worst giallo that I’ve ever seen. It’s significantly worse than the Gothic-giallo Seven Deaths in the Cat’s Eye, The Card Player (for my money Dario Argento’s worst movie), and such undistinguished titles as What Have They Done To Your Daughters, The Pyjama Girl Case and Watch Me When I Kill. It’s doesn’t even have the juicy ludicrousness of something like Umberto Lenzi’s Eyeball.
The plot is pretty simple: Renzo Marignano plays detective Cuthbert Campbell (!) who is investigating a series of Jack-the-Ripper type murders of prostitutes in London, and shares his thoughts about the case with a teacher friend (Andres Resino.) His chief suspect is Pedro (Paul Naschy), a former trapeze-artist and the husband of one of the victims. It appears that someone is trying to frame Pedro for these murders, but who and why? But really, it’s more a case of who cares? This is one of those giallos that suffers from being under-populated, with the list of possible suspects not being very long.
Jose Luis Madrid’s direction barely extends beyond pointing the camera at his actors and getting them to read their lines. The acting is poor, especially from the bit-players who look clueless throughout. Naschy is simply unappealing, and as for the limp he affects throughout - it’s as if he is auditioning for the Ministry of Silly Walks. But the most catastrophic bit of acting is when one of the prostitutes starts drunkenly raving about how awful men are - while Naschy hobbles and grunts away in the background. It reminded me of that demented scene in another Spanish shocker, 1981’s Pieces (anyone who’s seen it will known which one I mean. Who knows, could that scene be a sly homage to 7 Murders?) The dubbing only makes things worse, with god-awful cockney accents, what appears to be Australian accents, and one character who sounds American in one scene, then has a Scottish brogue a few scenes later. Visually, it’s cheap and ugly, from the wobbly sets and horrible décor, to the terrible lighting. The only fun to be had is during the location shots to look out for the number of people who look directly into the camera.