A 25-year-old man, working as a ward boy in a private hospital, murdered his old uncle in a fit of rage on Friday night. According to police, Ezhumalai (70) resident of Thirumurthy Nagar, Nungambakkam and wife Govindammal (60) had a property dispute with her brother Ponnuswamy. Following an argument, Mahadevan, son of Ponnuswamy, stabbed his uncle and aunt. Ezmualai was taken to a hospital where he died. Govindammal suffered injuries. Mahadevan is in hospital after consuming acid.