The man allegedly behind the murder of a journalist in Bihar's Siwan district was arrested today, along with three others, albeit in a different case. Police said Upendra Singh and three others were arrested for possession of liquor, which is now illegal under the state's new prohibition policy. Sources said the plan is to take them on remand and probe their role in the murder of Rajdeo Ranjan, the bureau chief of the Hindi daily Hindustan, who was gunned down on Friday.