Members of the Multi-jurisdictional Honor Guard, Officers Don Ramirez and Lou Perez from the Oak Brook Police Department and Sgt.Steve Woodham (right) from the Naperville Police Department raise the U.S. flag during a Peace Officers Memorial Observance at the Naperville Police Department on Tuesday, May 15, 2012 in Naperville. | Steven Buyansky~Sun-Times Media

Bill Bermes, the grandson of Naperville Police Chief Robert Worthel, who was killed in the line of duty in 1927, is escorted by Sgt. Mark Ksiazek as they approach to lay a rose under a memorial wreath during a Peace Officers Memorial Observance at the Naperville Police Department on Tuesday, May 15, 2012 in Naperville. | Steven Buyansky~Sun-Times Media

Naperville Police Sgt. Greg Bell, a member of the honor guard, stands at attention holding a folded U.S. flag during a Peace Officers Memorial Observance at the Naperville Police Department on Tuesday, May 15, 2012 in Naperville. | Steven Buyansky~Sun-Times Media

Naperville Police Chief David Dial welcomes guests to a Peace Officers Memorial Observance at the Naperville Police Department on Tuesday, May 15, 2012 in Naperville. | Steven Buyansky~Sun-Times Media

Members of the Multi-jurisdictional Honor Guard lower the U.S. flag to half staff during a Peace Officers Memorial Observance at the Naperville Police Department on Tuesday, May 15, 2012 in Naperville. | Steven Buyansky~Sun-Times Media

Officers Scott Beck and Jim Minett from Downers Grove Police Department place a wreath in front of the Naperville Police Department Memorial, to honor fallen police officers from DuPage County during a Peace Officers Memorial Observance at the Naperville Police Department on Tuesday, May 15, 2012 in Naperville. | Steven Buyansky~Sun-Times Media

Naperville Central High School students Claire Leitzen and Alec Kapicak sing after roses were place under a wreath during a Peace Officers Memorial Observance at the Naperville Police Department on Tuesday, May 15, 2012 in Naperville. | Steven Buyansky~Sun-Times Media

Commander Brian Cunningham, a member of the Pipes and Drums of the Naperville Police Department, play "Amazing Grace" on his bagpipe during a Peace Officers Memorial Observance at the Naperville Police Department on Tuesday, May 15, 2012 in Naperville. | Steven Buyansky~Sun-Times Media

Lisle Police Watch Commanders Ron Wilke and Randy Johnson observe a moment of silence for the 163 police officers killed last year in the line of duty during a Peace Officers Memorial Observance at the Naperville Police Department on Tuesday, May 15, 2012 in Naperville. | Steven Buyansky~Sun-Times Media

Commander William Hall of the West Chicago Police Department salutes West Chicago Police Officer Michael A. Browning, who was killed in the line of duty on April 20, 1992 during a Peace Officers Memorial Observance at the Naperville Police Department on Tuesday, May 15, 2012 in Naperville. | Steven Buyansky~Sun-Times Media