I'm a firm believer that rain can add atmosphere to any scene, whether on film, television, book or photograph. The downpour that accompanies many of the events at the beginning of this Duccio Tessari directed giallo is welcome after the very lengthy introduction, via a never-ending opening credits sequence introducing many starring characters.

The rainstorm adds additional horrific grit to the murder of beautiful student Françoise Pigaut (Carole André), after which toupee-sporting sports presenter Alessandro Marchi (Giancarlo Sbragia) is arrested. We then learn his wife is having an affair with his lawyer, and that even after Marchi's incarceration, further murders take place … 'The Bloodstained Butterfly' has garnered much praise for resisting the flamboyant nature of many giallos and concentrating, in a very measured way, on the various characters and possible murderers. The police investigations are methodical and Silvano Tranquilli's Inspector Berardi and his men spend as much time in the dark about things as we are. The reluctance to dwell on gore, sex or elaborate plot details tend to make many events quite dull viewing in my view.

Usual giallo standouts are very much in evidence here: Gianni Ferrio's score is wonderful, the locations, drenched in sun or hammered by rainfall, are spectacular throughout. The reveal at the end is entirely in-keeping with the restrained manner throughout the 95 minutes – satisfying but hardly spectacular.

You have to be a fan of the genre to watch those movies. A lot of sleaze and a lot of exploitation going on. Or you're movie mad like me and you watch almost anything that is suggested to you ... I roll like that. So this Giallo that is also part court room drama and has other elements to it at times, works like a mystery thriller would (or a whodunnit).

Decently told with enough sensationalism, action and nudity to keep anyone occupied who wants to be ... some very nice performances and the music works too. Editing is also a big part especially considering the murder that this movie begins with ... so a good movie overall that still won't get to those who dislike these types of movies ... but they are not the target (audience) ... so there's that.

Behind a typically abstruse giallo title (the plot's link to a butterfly of any kind is extremely tenuous) lies a film that rarely feels like a typical giallo, with more police procedure and courtroom drama than usual. Director Duccio Tessari's film opens in familiar territory with the murder of a young woman in a park, the killer, in raincoat and hat, making his escape, but witnessed by several people. The police investigate the crime scene, forensics gathering numerous pieces of evidence, all of which points to TV reporter Alessandro Marchi (Giancarlo Sbragia) as the guilty party. The rest of the first half of the film is dedicated to the trial of Allesandro, with dreary flashbacks and cross-examination making the film something of a chore to sit through.

Found guilty of murder, Allesandro is sentenced to life, but while he is in prison, the killings continue, the modus operandi the same as before, the culprit contacting the police with a whispered phone call. When Allesandro's mistress comes forward with vital information that seems to prove his innocence, Allesandro is freed (much to the annoyance of his wife, who also has a lover). After much intrigue, Tessari eventually pulls together all the plot threads for an unexpected twist ending that goes some way to make the duller moments seem a bit more worthwhile. As far as the death scenes go, they are extremely tame and likely to disappoint fans of Argento or Fulci, and despite a fair few attractive women, the level of nudity is also fairly low.

Perhaps the most notable things about the film are its police inspector's strange obsession with coffee, and the cop who falls over running down some stairs during a chase on foot through the streets of Milan (it looks unintentional and is never spoken of).

5.5/10, rounded up to 6 for IMDb.