Iowa Gov. Terry Branstad has ordered all flags on the Capitol grounds to be flown at half-staff on Friday to observe the Iowa Peace Officer Memorial Ceremony. During the ceremony, state leaders will honor four officers killed in the line of duty, including Urbandale Officer Justin Scott Martin and Des Moines Sgt. Anthony David Beminio, who were killed minutes apart on Nov. 2 in separate ambushes as they sat in their patrol cars.