President Obama paid tribute Tuesday to the fallen officers who gave their lives in the line of duty.
He said that, even though police are well trained and well armed, their mission is a peaceful one.
"Today, with heavy hearts, we honor those who gave their lives in the service of that mission," said President Obama. "Their families are in our thoughts and prayers as we remember the quiet courage of the men and women we have lost."
Berks County Sheriff Eric Weaknecht and Alecia Pagerly were in Washington for the ceremony. They took the trip in honor of Alecia's husband, Deputy Sheriff Kyle Pagerly, who was shot and killed while trying to serve a warrant in Albany Township on June 29.
Ofc. Robert Lasso, Freemansburg Police Dept. in Northampton Co., was also honored in Washington. He was shot and killed after responding to the report of a disturbance last August. His alleged killer, George Hitcho Jr. is currently on trial in Easton.
Pagerly and Lasso were two of four police officers killed in the line of duty in Pennsylvania last year.
"Let us take a moment to honor their bravery and remember all of those law enforcement officials who put their life on the line in the best interest of the commonwealth," said U.S. Sen. Bob Casey, D-Pa. "I will keep them and their families in my thoughts."
Gov. Tom Corbett ordered flags in Pennsylvania to fly at half-staff Tuesday in the officers' honor.
Congress created National Peace Officers Memorial Day -- May 15 -- 50 years ago to honor the memory of all law enforcement officers killed in the line of duty.