For a comparison: In Germany a sniper or a law enforcement officer killing a suspect is not necessarily specifically allowed in the law (3 out of 16 states don'

For a comparison: In Germany a sniper or a law enforcement officer killing a suspect is not necessarily specifically allowed in the law (3 out of 16 states don't have any special regulation concerning this). The legal theory to still allow shooting a hostage taker is called "(Aussergesetzlicher) Notstand", the situation where to protect one person from harm you need to inflict harm to another person. This does not make the action itself legal, but the person goes unpunished. It's actually a legal concept that I prefer over permitting killings by law enforcement.