Etiquette for Wearing a Mourning Badge
It is traditional for police officers to wear a black band over their badges in mourning when one of their fellow officers is killed in the line of duty. No national mourning badge band policy exists, but many agencies follow similar guidelines to ensure that they give this tradition the proper respect and gravity.
1 How Officers Wear a Mourning Band
The Officer Down Memorial Page suggests that officers wear a 1/2-inch-thick, solid black band horizontally across the center of their badges. You may see officers with star-shaped badges position the band at a slight diagonal, from 11 to 5 if looking at the badge like the face of a clock. Guidelines may vary among individual agencies. Some officers wear a black band with a blue stripe through the center, though this is not standard.
2 When Officers Wear a Mourning Band
When an officer is killed in the line of duty, other officers in her station or precinct usually wear a mourning band from the time of the officer's death until the end of the day 30 days later. Officers in other precincts or stations generally wear a band from the time of death until the end of the day of the funeral. Officers also wear bands at the funerals of retired police officers or those not killed in the line of duty, on Law Enforcement Officer Memorial Day, and at other line-of-duty memorial and dedication services.