Police have changed the investigation officer of police superintendent Babul Akter’s wife Mahmuda Khanam Mitu murder case.Assistant Commissioner of Detective Branch (DB) Kamruzzaman has been given the charge of the case instead of DB Inspector Rakibuddin.Anwar Hossain Additional Deputy Commissioner (public relations) of Chittagong Metropolitan Police (CMP) said the change has been made following an order taken by Chittagong Metropolitan Police Commissioner Iqbal Bahar on Saturday night.Earlier, miscreants gunned down Mahmuda Khanam, wife of Babul AKter, at Chittagong’s GEC intersection on June 5 while she went out from her residence to drop her son, Mahir Akhter, 7, for a bus to Chittagong Cantonment Public School and College around 6.30am.