Two-Edged Knife
Faca de Dois Gumes/Two Edge Knife (Murilo Salles, 1989)
Paulo is a rich lawyer who has a happy and comfortable family life, with his kid and very loyal to his wife. But when he finds out that the woman is cheating on him with his business partner and best friend, he decides to execute a perfect plan that involves murdering both and easily getting away with murder....