Arrest by federal agency will require DNA sample. Next thing you know they will require DNA sample as requirement for future biometrics on naturalization applications.
http://www.washingtonpost.com/wp-dyn/content/article/2008/04/16/AR2008041602729.html?hpid=topnews
http://www.washingtonpost.com/wp-dyn/content/article/2008/04/16/AR2008041602729.html?hpid=topnews