A retired Sashastra Seema Bal(SSB) man who was absconding after allegedly killing his wife, son and uncle, succumbed to his injuries sustained during an exchange of fire with police on Tuesday morning, a senior police officer said.The man who had taken voluntary retirement from the SSB had on Monday shot dead his wife at his residence in Hukan Pukhuri and then shot at his 20-year old son severely injuring him on the head when he was sleeping, he said.He then went to his maternal uncle's house at nearby Kumaranisiga on NH-37 and shot at his uncle seriously injuring him before he fled away, police said.Both his son and uncle were rushed to the Assam Medical College and Hospital (AMCH) where they succumbed to their wounds.On a tip off about the man hiding in an abandoned building of the Fisheries Department, police cordoned off the area and asked him to surrender, Dibrugarh Superintendent of Police Sreejith T told PTI."We negotiated with him for three hours asking him to give up, but he refused. Instead he started firing at the police from his licenced pistol that he had used to allegedly kill his three family members," said the SP who led the search operation along with Additional SP Padmanabh Baruah.The police retaliated at around 3 am, injuring the man.The accused was taken to the AMCH where he succumbed to his injuries, the SP said.Police said, the man was reported to be an alcoholic and used to indulge in gambling.