Senior Congress leader Mallikarjun Kharge on Thursday said "anti-progressive people" were responsible for the murder of journalist-activist Gauri Lankesh and all states should take a united stand to catch the culprits."I don't want to say now..this party has killed her or that party has killed. But I am sure that anti-progressive people and those who are opposed to Gauri Lankesh might have taken advantage of this situation," Kharge told a news channel."I don't know to get into the details and don't want to go on assumptions (about who killed her)," he added when asked about her killers.Kharge said: "A Special Task Force has been constituted and the team is very good. About 21 people are involved in that. Those three teams will work vigorously and whatever is the truth will come out."Asked about the Kalburgi murder case, Kharge said: "Such things can be brought out in public only if all work together, whether it is Maharashtra, Karnataka and others." "Therefore, Maharshtra should also support. Whatever feedback the government of Karnataka has got, they should also support. "So, everybody should take a united stand to catch hold of the culprits. Maharashtra's Sanatan Sanstha people are there in Kolhapur and Pune," he added.Lankesh, 55, editor of popular Kannada tabloid Gauri Lankesh Patrike, was shot dead at her Bengaluru home by three unidentified assailants on Tuesday night.