Study finds terrorists still exploiting US immigration laws

Some immigrants used false documents to enter the United States, others let their legal visas expire once in the country. And at least 21 foreign nationals became naturalised US citizens before being charged or convicted as terrorists.

In all, at least 94 foreign-born visitors accused of terror activity between 1993 and 2004 exploited federal immigration laws to enter or remain in the United States, according to a study being released today.