Here is an interview with Khashoggi's editor at the Washington Post (a rather young and quite attractive black woman, BTW) on her reaction to the Saudi "fistfight" explanation for his death. What's most interesting is she drops a bombshell that US intelligence knew there was an active plot to capture/kidnap Khashoggi, which suggests to me that he or the Washington Post may have been tipped that he was a target of an active plot and he undertook this Turkish trip at his own grave danger:
https://www.cnn.com/2018/10/20/opinions/saudi-arabia-khashoggi-statement-robertson-intl/index.html
Of course if that is true, there is likely nothing that could have been done to have prevented Khashoggi from eventually being killed. My opinion, he should have stayed in the USA, had the Turkish woman join him here and then elope with her, here. It's not like he would have been safe walking the streets in DC or anywhere, but at least he would have made harder this kind of strongman ambush.
https://www.cnn.com/2018/10/20/opinions/saudi-arabia-khashoggi-statement-robertson-intl/index.html
Of course if that is true, there is likely nothing that could have been done to have prevented Khashoggi from eventually being killed. My opinion, he should have stayed in the USA, had the Turkish woman join him here and then elope with her, here. It's not like he would have been safe walking the streets in DC or anywhere, but at least he would have made harder this kind of strongman ambush.