SCIUTTO: Turning now to terror. Police in Belgium say they have detained three more people in connection with the investigation into last year's horrible attacks in Paris. The arrest happened in a suburb of Brussels. A judge will decide tomorrow if the three can be held by police. Today's raid follows operations carried out last week where police in Brussels detained half a dozen suspects. Meanwhile, the fight against terror moved to Capitol Hill today. The Senate Foreign Relations Committee heard from witnesses about the transnational spread of terror, including from Matthew Olsen. He's the former director of the National Counterterrorism Center. Here's what he said about what he believes the U.S. needs to do to defeat terrorism, including stopping attacks here at home.</s>MATTHEW OLSEN, FMR. DIRECTOR, NATIONAL COUNTERTERRORISM CENTER: One is a surge in our intelligence capabilities. A surge would enhance our technical surveillance capabilities, develop sources to penetrate ISIS and form closer relationships with intelligence services. This would address the gaps that exist because of the use of encryption and it would address the gaps that exist because we've -- the legal disclosures of our intelligence surveillance capabilities, which are hampering our intelligence community today.</s>SCIUTTO: Senator Bob Corker is the chairman of the Foreign Relations Committee. He joining me -- he's joining me now live from Capitol Hill. Senator Corker, thank you for taking the time.</s>SEN. BOB CORKER (R-TN), CHAIRMAN, SENATE FOREIGN RELATIONS COMMITTEE: Thank you, Jim.</s>SCIUTTO: So we just heard Matt Olsen. He knows the issue very well, he spent a lot of time at the director of the National Counterterrorism Center, talking about this surge in intelligence to combat ISIS, specifically the issue of encryption, terrorists going dark. Do you agree that this is a crisis in terms of putting a damper on the ISIS threat?</s>CORKER: There was no question that greater intelligence sharing and gathering is very important.
Senate Terror Hearings; Interview with Sen. Bob Corker.