And today, Secretary Napolitano and the Attorney General Eric Holder are formalizing a joint task force between the Department of Homeland Security and the Department of Justice that will leverage the investigative capabilities of both agencies to work with Mexico in tracking down the perpetrators.

WHITEHOUSE: Press Briefing

"In an immense show of force, police have shown their presence, " said Kanene Holder, a spokeswoman for the Occupy Wall Street movement.

CNN: New York court upholds eviction of Occupy protesters

In a heated exchange with Senator Ted Cruz during a hearing earlier in the day, Mr Holder said it was not appropriate to use lethal force - "drones, be it guns or whatever else" - on a US citizen.

BBC: US & Canada

Speaking hours later on the Senate floor, McConnell said Paul deserves an answer from Attorney General Eric Holder on whether the Obama administration has authority to use lethal force against a suspected terrorist who is a U.S. citizen.

NPR: Senator Uses Old-Style Filibuster On CIA Nominee

At the hearing Thursday, Holder said the money is needed for special equipment and facilities for the highly classified task force work necessary to enable the detention facility to be closed.

CNN: Holder: Suspected Gitmo terrorists won't be freed in U.S.

Mr Holder did not discuss any current programmes, but said the threat posed by extremists justified the use of force.

BBC: US Attorney General justifies terrorism kill policy