Photographs of Military Dead

I was just watching Ted Koppel’s reading of the names of the service members who have died in the Iraq war while showing their photographs. My question is where do the media get the photographs of service members killed in action?

Something I noticed were that almost all of the sailors and Marines had formal photographs in dress uniforms. On the other hand, the army and air force members had a broad mix of pictures. A few were in dress uniform, but most were a mix of shots in field uniforms or in civilian clothes, and there were quite a few that had no photograph. Is there something that accounts for this difference?

I don’t think the military starts keeping official photos on file until you hit the rank of E7 (my Senior Chief sent in an update just last week) but I don’t think that they would release those photos under the Freedom of Information Act, either. My WAG is that they just call the family members and ask for a photo and permission.