Obama speaks at National Peace Officers Memorial Service (25 images)

US President Barack Obama (back) delivers remarks at the National Peace Officers Memorial Service, an annual ceremony honoring law enforcement who were killed in the line of duty, on Capitol Hill in Washington DC, on May 15, 2012. Also in the picture is an honor guard, a member of the Capitol Police. UPI/Michael Reynolds/Pool

U.S. President Barack Obama , Attorney General Eric Holder and Secretary of Homeland Security Janet Napolitano attend at the 32st Annual National Peace Officers Memorial Service at the West Front Lawn of the U.S. Capitol in Washington, DC on May 15, 2013. Senior officials including President Barack Obama attend the annual event to honor law enforcement who were killed in the line of duty in the previous year. UPI/Olivier Douliery/Pool

Law enforcement personnel salute during the National Anthem during the National Peace Officers' Memorial Service on the West Front of the Capitol Building on May 15, 2013 in Washington, D.C. UPI/Kevin Dietsch

President Barack Obama arrives for the National Peace Officers' Memorial Service on the West Front of the Capitol Building on May 15, 2013 in Washington, D.C. UPI/Kevin Dietsch