La semana del asesino
A young man, Marco, working as a butcher, accidentally kills a taxi driver. His girlfriend Paula wants to go to the police so he has to kill her too. He then has to kill his brother, his brother’s fiancée and his father, who have become suspicious. He gets rid of the bodies by taking them to a slaughter house.
Starring Vicente Parra, Emma Cohen, Eusebio Poncela, Lola Herrera, Vicky Lagos, Ismael Merlo, Fernando Sánchez Polack, Charly Bravo, Rafael Hernández, Goyo Lebrero
Watch "La semana del asesino" from streaming services shudder-shudder-subscription, Amazon released in 1972. It's a drama and horror movie, and has a rating of 6.3 out of 10 from Imdb which is usually fine for this kind of movie.