A 22-year-old man was arrested on Friday for allegedly killing his 65-year-old maternal uncle with a spear following a family altercation at Mahasahani village under Aul police station limits on Thursday night. A 22-year-old youth, Karuna Das, was arrested in Kendrapara, Odisha, for allegedly killing his 65-year-old maternal uncle, Giridhari Das, with a spear following a family altercation on Thursday night.