if people outsource "target detection" to some software, they personally are responsible for what it does.
if people outsource the actual murdering to some software, they personally are responsible for those deaths.
a human made the decision to permit this and the entire consequences of it should be on their head. we can never ever let the people who wrote and/or approved the software escape blame for what it does.
we're already seeing this with self-driving cars - which individual at uber should be serving sentences for their cars killing someone? or did we accidentally make murder completely legal as long as you obfuscate the cause chain enough?