English to Spanish Social Sciences Government / Politics Procedures Manual

***Lead Advance Agent*** means the Secret Service Agent in charge of all security arrangements. This person is responsible for all sites to be visited by the protectee, and is a representative of the Office of Protective Operations (Secret Service Headquarters).

Any ideas how to convey this into Spanish? I uderstand the concept, but I cannot come up with a decent Spanish equivalent that will convey this idea. Help!

Thank you.
Mariela