To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Share Embed Share URL Video File Node URL Embed Code <iframe title="MRC TV video player" width="640" height="360" src="https://www.mrctv.org/embed/120850" allowfullscreen></iframe> CNN's national security analyst Peter Bergen suggested that "right-wing extremists" could be behind Monday's Boston Marathon bombings.