From left: In January 2013, Department of Defense Chief of Staff Jeremy Bash, Secretary of Defense Leon Panetta, Joint Chiefs of Staff Chairman Martin Dempsey and Col. David Lapan walk through the Pentagon. (DoD photo / Erin A. Kirk-Cuomo / Flickr) DHS spokesman leaving for think tank David Lapan is leaving his post for a job with the Bipartisan Policy Center, CyberScoop has learned. Oct 18, 2017 By Shaun Waterman