American airmen murdered in Frankfurt, but who could be responsible?

When a normal person enters the chicken house to find all the chickens with their heads bitten off he thinks “fox”. In other words the most obvious culprit comes instantly to mind and, instead of wasting time looking for a rabbit with blood on its face, the normal person looks for a fox. With media people the process is different. Media people look for the rabbit first and only reluctantly consider the fox a day later if no rabbit is found and the fox simply won't go away and hide no matter how they stroke it.