LONDON — Here’s what the United Nations report on Israel’s raid last year on the Turkish-flagged Mavi Marmara had to say about the killing of a 19-year-old U.S. citizen on board:

“At least one of those killed, Furkan Dogan, was shot at extremely close range. Mr. Dogan sustained wounds to the face, back of the skull, back and left leg. That suggests he may already have been lying wounded when the fatal shot was delivered, as suggested by witness accounts to that effect.”

The four-member panel, led by Sir Geoffrey Palmer, a former prime minister of New Zealand, appears with these words to raise the possibility of an execution or something close.

Dogan, born in upstate New York, was an aspiring doctor. Little interested in politics, he’d won a lottery to travel on the Gaza-bound vessel. The report says of him and the other eight people killed that, “No evidence has been provided to establish that any of the deceased were armed with lethal weapons.”

I met Dogan’s father, Ahmet, a professor at Erciyes University in Kayseri, last year in Ankara: His grief was as deep as his dismay at U.S. evasiveness. It’s hard to imagine any other circumstances in which the slaying in international waters, at point-blank range, of a U.S. citizen by forces of a foreign power would prompt such a singular American silence.