Giallo is Italian for 'yellow', it's also a genre of film you should be familiar with if you're any kind of movie buff, and, if you know about giallo at all, you know that Dario Argento is the master of giallo and, in fact, has a movie called Giallo! What are the odds?
The story here is a bit strange, there's a serial killer on the loose (and apparently he's been on the loose for a while) and Detective Adrian Brody is on his trail. Now, a super model has been grabbed by our killer and her sister goes to Brody to get him to search for her before it's too late!
The problem with this movie is that it's just a narrative mess, Brody is a 'New York' cop who's been looking for this killer for years, and has an obsession with catching serial killers in general due to a childhood trauma. How he's become acquainted with this particular killer isn't really explained. When the model's sister goes to the police, she's told to follow a food delivery to the basement where Brody is brooding over walls filled with gruesome pictures of murder victims...are these all victims of our killer, or just random victims of different killers...that's also never really explained! The killer, when we meet him is incredibly jaundiced (making him yellow...hence the name of the movie...well, one of them anyway), why he's that way we don't really know, we just know he's sick and needs medication...and we only know that because Brody finds him apartment and pours out all his meds!
In the end, the serial killer doesn't get a lot of screen time, the detective spends most of his time brooding about the killer than actually looking for him and the model's sister spends an inordinate amount of time looking distraught. Overall, it's amazing that this guy gets caught at all, and, in the movie, it's a complete coincidence that he does...and then, as the search goes on for the missing model, the way she's discovered is one of the dumbest in movie history!!
I'm giving Giallo 1 out of 4 cigars, it's not dramatic, it's not tense, it's mostly Adrian Brody attempting to look dark, deep and troubled for an hour and a half. There are much better Argento movies, look for nearly any one of those, Giallo is a movie best left on the shelf until dust eventually covers it over completely!