Hereditary

“No, you don’t understand,” the woman mumbles. “He’s a good boy. Too gentle to hurt a fly!” She sobs into a handkerchief.
Her son is thirty-seven, single and unemployed. He lives in her basement, collects action figures and trolls the internet. Two weeks ago he accidentally found out that his mother has been ill for some time and is going to die soon.
He suffered a psychotic break. We’ve found him wrist-deep into his fourth victim.
I would feel sorry for her, but watching her passively watch the police take him away… I can tell he comes by it honestly.