This article lightly describes how immunity might work, but despite the title fails to present any recourse besides the obvious "maybe we shouldn't let those specific security guards back into the country after they leave."

https://www.washingtonpost.com/news/politics/wp/2017/05/17/h...

Not stupid, and they most likely have immunity, if they are officially a part of the delegation.

That's my understanding too. Although I believe that the US could ban those individuals from having immunity in the future and eject them from the country, which is certainly what I'd advocate for here.

There's a wiki article somewhere that was brought up when this discussion happened on reddit that states that members of security details aren't usually granted immunity, only consular officials are.

EDIT: I found it [0]

[0]: https://en.wikipedia.org/wiki/Diplomatic_immunity#Diplomatic...

Technically Turkey could wave the diplomatic immunity, but considering who ordered the attacks.. though luck

Or my understanding is that the US can revoke their diplomatic credentials and expel them at any time, and that tends to be a more common response to a serious crime than actual waiver of immunity and prosecution.

If they do this in the USA, imagine what they do back home. Wild stuff.