A former Central Reserve Police Force (CRPF) constable shot dead his 29-year-old son here on Monday, police said.Rakesh Rawat had a verbal spat with his son before allegedly shooting him him with a rifle. The neighbours found the body."We have arrested Rawat and seized the rifle," said police officer Sapan Mehta.The neighbours said the son had joined Rawat a few days back. The former trooper had been living alone for a long time.