re: How was the Bonnie and Clyde ambush legal?

One tenth of a second before firing the officers shouted: 'Put your hands up.' Bonnie and Clyde were just too slow.

Edit: True story. Years ago a guy shot and killed an officer in Georgia. He was spotted in the woods hiding crouched behind a fallen tree. The leader of the posse shouted 'Come out with young hands up.' He waited two seconds and then shouted 'Fire!'
The coroner reported that the deceased had 30 bullet wounds. I saw the TV interview later that day:
Reporter: 'Why did you shoot the suspect 30 times?'
Sheriff: 'We ran out of bullets.'