A gunman of the Mansa Deputy Commissioner allegedly shot dead his son and seriously injured his wife and another son before shooting himself dead at their under-construction house in Jhujhar Nagar on Mansa Khurd Road on Tuesday. Sources said the family had shifted to the house just the previous evening.Head Constable Gurwinder Singh allegedly opened fire on his family members before turning the weapon on himself. The deceased have been identified as 36-year-old Gurwinder and his 17-year-old son, Gurjot. The injured, 33-year-old Harpreet Kaur and 13-year-old son Dilshan were referred to a hospital in Ludhiana for treatment. Harpreet’s condition was reported as critical.Mansa Senior Superintendent of Police Vaibhav Chaudhary, who visited the spot, said the police had initiated an investigation. “The preliminary investigation suggested that the incident stemmed from a family dispute. We have seized the official weapon of the deceased from the spot. A forensic team is collecting the evidence,” the SSP said.Meanwhile, an elderly woman living in the neighbourhood said the injured woman lay outside her residence and pleaded for help after Gurwinder opened fired on the family.