It's incidents like this
Maher Shakirat summoned three of his sisters to discuss a family uproar after one of them, Rudaina, was thrown out by her husband for an alleged affair. Maher listened to Rudaina's denials, and her sisters' pleas that they were not covering up the affair. Then he forced the three women to drink bleach before strangling Rudaina, who was eight months pregnant. The other sisters tried to flee but Maher caught and strangled Amani, 20. The third, Leila, escaped but was badly injured by the bleach.
I'm pretty sure I can come up with a few pithy phrases to accurately describe these type of people, but it would do my blood pressure no good.