Family members of slain Phoenix police officer David Glasser are in Washington D.C. honoring him and all officers killed in the line of duty.

They joined President Donald Trump in the Oval Office as he signed a proclamation declaring May 15 as Peace Officers Memorial Day. Previously, May 15 had been proclaimed Peace Officers Memorial Day and the entire week National Police Week by President John F. Kennedy on October 1, 1962.

Officer Glasser was fatally shot by a suspect nearly a year ago as he assisted five other officers on a robbery in Laveen. He was a 12-year veteran of the force.

This year, 48 officers were killed in the line of duty nationwide.

EDITOR'S NOTE: This story has been updated to provide historical context for Peace Officers Memorial Day.