A 78-year-old retired army colonel allegedly shot himself dead with his licensed pistol at his residence here on Thursday, police said.Leela Singh was a resident of Rail Nagar in the Shyam Nagar police station area.Shyam Nagar SHO Hari Singh Doodhwal said Singh, who had reportedly been suffering from mental health issues, went to his room around 10.30 am and allegedly shot himself in the head.His wife, daughter-in-law and grandchildren were present in the house at the time of the incident, police said.After receiving information from the police control room, a police team reached the spot and called forensic experts to examine the scene.The licensed pistol was seized, and the body was handed over to the family after post-mortem.The exact reason behind the suspected suicide is yet to be ascertained, and further investigation is under way, the SHO said.