experts conduct work on the site to ensure security. rebel leaders claim to have the plane's cockpit voice and data recorders which may hold critical information about mh 17's last moments. in audio intercepts released by the ukrainian government, the alleged commander says moscow is interested in the black boxes and urges his subordinate to find them. cnn cannot independently confirm the authenticity of that audio. meanwhile u.s. intellgence points to the mounting evidence of russia's involvement, including evidence that pro-russian rebels secretly moved a heavy arsenal of weapons into place days before the crash. >> we have a video showing a launcher moving back through a particular area there out into russia with at least one missing missile on it. so we have enormous input about this which points fingers. >> reporter: this is that video