Time to get a little sociological in security terms. Want to get a sharper idea of who might be approaching your entry points? Maybe not, but maybe some methodology is worth considering. Like Social Identity Theory, as explained and promoted in this post on Homeland Security Watch.
Christopher Bellavita writes that “Two of my colleagues – David Brannan and Anders Strindberg – argue in their book A Practitioner’s Way Forward: Terrorism Analysis that terrorism research has been conducted without much attention to analytical rigor. They believe SIT can help provide that rigor.” So add some “rigor” to the protection of your gates.