The Metropolitan Police Circle, Sorhakhutte on Friday nabbed an alleged arms trader in possession of a loaded pistol from Shantinagar. The arrestee has been identified as Karsang Lama (21) of Kavre. DSP Somendra Singh Rathore said Lama was held with a pistol and five bullets that he was about to sell to a criminal group active in the Kathmandu Valley. Police have launched an investigation to ascertain the source and final destination of the firearm, said Rathor.