I saw this on the Viet Nam Veterans against Kerry.
I don't know what the rules of engagement, in the Delta, in a free fire zone were, but you couldn't shoot just anyone, you had to receive fire or observe the enemy under arms, then you could do pretty much as you pleased as long as you faced an armed foe.
As a note to this; No matter what what you saw on "Combat" or read in your history books or WW2 movies, if you are a civilian in a war zone and you are stupid enough to be caught in a battle, you are likely to get dead, as we used to say. Targets of opportunity is cowboy talk and an excuse for poor discipline, kinda like a deer hunter making sound shots, they either got guns or they don't.
While in command of Swift Boat 44, Kerry and crew operated without prudence in a Free Fire Zone, carelessly firing at targets of opportunity racking up a number of enemy kills and some civilians.
His body count included a woman, her baby, a 12 year-old boy, an elderly man and several South Vietnamese soldiers.
"It is one of those terrible things, and I'll never forget, ever, the sight of that child," Kerry later said about the dead baby. "But there was nothing that anybody could have done about it.
It was the only instance of that happening.
Kerry said he was appalled that the Navy's ''free fire zone'' policy in Vietnam put civilians at such high risk.