Federal prosecutors say a Massachusetts Air National Guardsman charged with leaking highly classified military documents took "a series of obstructive steps" intended to prevent investigators from understanding the scope of what he allegedly did. Subscribe to WCVB on YouTube now for more: http://bit.ly/1e8lAMZ Get more Boston news: http://www.wcvb.com Like us: https://www.facebook.com/wcvb5 Follow us: https://twitter.com/WCVB Instagram: https://www.instagram.com/wcvb5/