Medal of Honor for Civilian police? As soon as the military start receiving the Public Safety Officer Medal of Valor given to police. Don’t mix the apples and the oranges. The police forces have their own system of awards.
Yes of course. They put their lives on the line to save our troops, in a situation just as dangerous as one encounter find in many overseas combat situations.
Moreover, there's no doubt that they were fighting against a genuine enemy of the USA, a man who in fact called himself a "soldier" of Allah.
Finally, it may be a bit misleading to think of them simply as "civilian police" since they are Department of Defense employees and they're an integral part of the military installation at Ft. Hood.