LUCKNOW: The son of former BSP MLA Shamsher Bahadur Aman , was arrested on Friday in connection with the murder of a 20-year-old engineering course dropout who was stabbed the day before by a group of youths at the Gomtinagar Extension area here.“Bahadur was not physically present at the scene of the crime, but those who executed the crime were in touch with him throughout. We have ample evidence of calls being made by those present at the spot to Bahadur,” police said. Police have so far detained five students of the university where the deceased studied earlier. “We have traced six people behind the murder of Prashant Singh , including the prime conspirator,” Lucknow commissioner Sujeet Pandey said.Charges under National Security Act will be imposed on Aman and on all the conspirators of the crime, because their act was intended to spread terror among people, police said.