Miss Forbes' Murder Mystery

There are so many aspects of Miss Forbes' Summer of Happiness to analyze, that I feel like her murder mystery is often overlooked. This is probably because there are not many hints as to who killed her at first glance, but out of context there are clues that lead me to think that the murderer of Miss Forbes is the boys scuba instructor and Miss Forbes' love interest, Oreste.
With the introduction of Oreste to the story, the author Marquez puts emphasis on the fact that Oreste always carries knives around his belt and insists on using hand to hand combat when he hunts. This is the first clue, as Miss Forbes cause of death was multiple stab wounds. Later in the story, Miss Forbes expresses her feelings for Oreste, as she finds him attractive, this established an emotional connection between them that seems strange and abrupt, similar to how it would be if Oreste was in fact the murderer.
There is an ancient Greek play called "Orestes", in which a character in the play named Orestes kills his mother. Oreste is connected to ancient Greece in another way when he is described as looking like a sea animal. Although Miss Forbes isn't Orestes' mother, she is an older dictatorial person in Oreste's life, similar to his mother in the play.
It seems like there are too many fingers pointing at Oreste for him to not be the murderer of Miss Forbes. This aspect of the story usually is neglected, while most focus on the personality of Miss Forbes, but I believe this murder mystery has enough to be deeply analyzed.