Capitol Police had beefed up security before gunman entered

If an armed gunman carrying crack cocaine can get into the U.S. Capitol, what could terrorists with a practiced plan do?

Capitol Police say they beefed up patrols last month after lieutenants expressed concerns about security around the Capitol Visitors Center, but 20-year-old Carlos Greene was still able to storm the Capitol on Sept. 18 before civilian employees tackled him in a basement office.