They were tried and found guilty of treason.

他们受到了审判并被处以叛国罪。

《柯林斯英汉双解大词典》

On the other hand, a "no" answer would have made him a traitor to Rome and guilty of treason.

另外，若回答“不可以”，将会让他成为罗马帝国的叛徒，被判以叛国罪。

youdao

First, they said, he could not be guilty of treason against Virginia, because he was not a citizen of Virginia.

他们说，第一、他不应该受到背叛维吉尼亚罪的指控，因为他根本就不是维吉尼亚公民。

youdao

First,they said, he could not be guilty of treason against Virginia, because he was not a citizen of Virginia.

VOA: special.2009.07.02

John Brown was tried in nearby Charles Town and found guilty of treason and murder.

VOA: special.2009.11.06

He was found guilty of treason for leading an armed separatist campaign in Turkey in which more than 30, 000 people died.

BBC: Abdullah Ocalan is serving a life sentence for treason

And when the High Court convicted the 2000 coup leader, George Speight, of treason and sentenced him to death, the government accepted the guilty verdict.

ECONOMIST: The judges' growing power