Major Cities Increase Security After Boston Marathon Bombings
/ CBS News
A police officer with his K-9 companion keeps guard as a Long Island Rail Road train from New York City arrives at the station on April 15, 2013 in Hicksville, New York. (Photo by Bruce Bennett/Getty Images)
Cities Increase Security After Boston Marathon Bombings
A policeman secures the area in front of the White House in Washington on April 15, 2013 after blasts rocked the finish line of the Boston marathon. (MLADEN ANTONOV/AFP/Getty Images)
Cities Increase Security After Boston Marathon Bombings
Police secures the area in front of the White House in Washington DC on April 15, 2013 after blasts rocked the finish line of the Boston marathon. (MLADEN ANTONOV/AFP/Getty Images)
Cities Increase Security After Boston Marathon Bombings
Police secures the area in front of the White House in Washington on April 15, 2013 after blasts rocked the finish line of the Boston marathon. (MLADEN ANTONOV/AFP/Getty Images)
Cities Increase Security After Boston Marathon Bombings
Secret Service members are seen on the roof of the White House on April 15, 2013 in Washington, DC. Shortly after the Boston blasts, Secret Service officers cordoned off an area adjacent to the fence at the front of the North Lawn of the White House on Pennsylvania Avenue. (MANDEL NGAN/AFP/Getty Images)
Cities Increase Security After Boston Marathon Bombings
New York Police Department officers stand at the edge of Times Square in Manhattan on April 15, 2013. The city has announced it will implement heightened security measures in response to the bombings at the Boston Marathon. (Photo by Mario Tama/Getty Images)
Cities Increase Security After Boston Marathon Bombings
Seen from the inside of the White House compound, tourists stand behind a police line after Pennsylvania Avenue was closed on April 15, 2013 in Washington. Shortly after the Boston blasts, Secret Service officers cordoned off an area adjacent to the fence at the front of the North Lawn of the White House on Pennsylvania Avenue. (MANDEL NGAN/AFP/Getty Images)
Cities Increase Security After Boston Marathon Bombings
New York Police Department officers gather at the edge of Times Square in Manhattan on April 15, 2013. The city has announced it will implement heightened security measures in response to the bombings at the Boston Marathon. (Photo by Mario Tama/Getty Images)
Cities Increase Security After Boston Marathon Bombings
U.S. Secret Service and U.S. Park Police officers stand guard on Pennsylvania Avenue in front of the White House April 15, 2013 in Washington, DC. Security around the White House was tightened after two explosions went off near the finish line of the Boston Marathon. (Photo by Alex Wong/Getty Images)
Cities Increase Security After Boston Marathon Bombings
U.S. Secret Service and U.S. Park Police officers stand guard on Pennsylvania Avenue in front of the White House April 15, 2013 in Washington, DC. Security around the White House was tightened after two explosions went off near the finish line of the Boston Marathon. (Photo by Alex Wong/Getty Images)
Cities Increase Security After Boston Marathon Bombings
New York Police Department officers gather in Times Square in Manhattan on April 15, 2013. The city has announced it will implement heightened security measures in response to the bombings at the Boston Marathon. (Photo by Mario Tama/Getty Images)
Cities Increase Security After Boston Marathon Bombings
Policemen man their post at New York's Times Square after security was boosted following blasts that occurred at the finish line of the Boston marathon April, 15, 2013. (EMMANUEL DUNAND/AFP/Getty Images)
Cities Increase Security After Boston Marathon Bombings
A New York City police officer with the 78th Precinct patrols outside the Barclays Center prior to a Brooklyn Nets basketball game on April 15, 2013 in Brooklyn. Police say they have stepped up security following explosions at the Boston Marathon. (Photo by Bruce Bennett/Getty Images)
Cities Increase Security After Boston Marathon Bombings
New York City police officers patrol outside the Barclays Center prior to a Brooklyn Nets basketball game on April 15, 2013 in Brooklyn. Police say they have stepped up security following explosions at the Boston Marathon. (Photo by Bruce Bennett/Getty Images)
Cities Increase Security After Boston Marathon Bombings
Cars stop at a checkpoint at the entrance of Los Angeles International Airport after security was increased following mutiple expolsions during the 117th Boston Marathon on April 15, 2013. (Photo by Kevork Djansezian/Getty Images)
Cities Increase Security After Boston Marathon Bombings
A New York Police Department officer inspects a man's bag in Grand Central Terminal in Manhattan on April 15, 2013 in New York City. The city has announced it will implement heightened security measures in response to bombings at the Boston Marathon. (Photo by Mario Tama/Getty Images)
Cities Increase Security After Boston Marathon Bombings
French soldiers patrol on April 16, 2013 in front of the Eiffel Tower in Paris. (FRED DUFOUR/AFP/Getty Images)
Cities Increase Security After Boston Marathon Bombings
French soldiers patrol on April 16, 2013 in front of the Eiffel Tower in Paris. (FRED DUFOUR/AFP/Getty Images)
Cities Increase Security After Boston Marathon Bombings
French police patrol on April 16, 2013 on the Trocadero plazza in front of the Eiffel Tower in Paris. (FRED DUFOUR/AFP/Getty Images)
Cities Increase Security After Boston Marathon Bombings
Secret Service Uniformed Division members stand keep watch on Pennsylvania Avenue and 17th Street, near the White House on April 16, 2013 in Washington, DC. (Photo MANDEL NGAN/AFP/Getty Images)
Cities Increase Security After Boston Marathon Bombings
A police van patrols around Ground Zero at the World Trade Center building site, in New York, April, 16, 2013. The city went on high alert a day after two explosions happened in quick succession near the finish line at the Boston Marathon. (EMMANUEL DUNAND/AFP/Getty Images)
Cities Increase Security After Boston Marathon Bombings
Metropolitan Transit Authority police officers keep watch during the morning commute in Grand Central Terminal on April 16, 2013. The city announced it has continued increased security one day after the Boston Marathon bombings. (Photo by Mario Tama/Getty Images)
Cities Increase Security After Boston Marathon Bombings
National Guard soldiers keep watch during the morning commute in Grand Central Terminal on April 16, 2013. The city announced it has continued increased security one day after the Boston Marathon bombings. (Photo by Mario Tama/Getty Images)
Cities Increase Security After Boston Marathon Bombings
A police K-9 unit stands by as train passengers pass through Penn Station on April 16, 2013 in New York City. Police were out in force throughout New York, a day after explosions near the finish line of the Boston Marathon killed 3 people and wounded more than 170 others. (Photo by John Moore/Getty Images)
Cities Increase Security After Boston Marathon Bombings
A police K-9 unit stands by as train passengers pass through Penn Station on April 16, 2013 in New York City. Police were out in force throughout New York, a day after explosions near the finish line of the Boston Marathon killed 3 people and wounded more than 170 others. (Photo by John Moore/Getty Images)
Cities Increase Security After Boston Marathon Bombings
An Amtrak police special operations unit stands by outside of Penn Station on April 16, 2013 in New York City. Police were out in force throughout New York, a day after explosions near the finish line of the Boston Marathon killed 3 people and wounded more than 170 others. (Photo by John Moore/Getty Images)
Cities Increase Security After Boston Marathon Bombings
A police K-9 unit stands by outside of Penn Station on April 16, 2013 in New York City. Police were out in force throughout New York, a day after explosions near the finish line of the Boston Marathon killed 3 people and wounded more than 170 others. (Photo by John Moore/Getty Images)
Cities Increase Security After Boston Marathon Bombings
A police K-9 unit dog sniffs newspaper boxes for explosives outside of Penn Station on April 16, 2013 in New York City. Police were out in force throughout New York, a day after explosions near the finish line of the Boston Marathon killed 3 people and wounded more than 170 others. (Photo by John Moore/Getty Images)
