The mother of Sylhet youth Raihan Ahmed has demanded the arrest of everyone involved in killing her son and removing the evidence of murder.   Salma Begum made the demand in a press conference at her house in Neharipara of Sylhet city on Saturday.   On the day of the incident, Raihan was wearing a T-shirt and blue trousers but when he was brought to the hospital, he was seen wearing clothes that did not fit his body, she said.   Salma Begum said police are yet to hand over her son’s mobile phone and wallet.   “They killed my son within four hours,” she said, demanding the arrest of officers who helped Sub-Inspector Akbar flee.   After the autopsy, doctors said there were 111 injury marks on Raihan’s body and two of his nails were pulled out.   “I’m not doubting the police investigation as they have already arrested SI Akbar. But still, it’s not clear why they killed my innocent boy,” the mother said.