Subway Explosion Security Screening

This undated photo shows stand-off explosion detection units deployed in a Los Angeles Metro. U.S. Sen. Chuck Schumer, D-N.Y., wants the Transportation Security Administration to speed up plans to equip transit hubs with screening devices that can detect suicide vests like the one that exploded in a New York City subway tunnel. Schumer said Sunday that the devices are urgently needed in New York City and other busy transit areas. (LA Metro/Dave Sotero via AP)