Double Criminality，双重犯罪原则，或双重归罪原则，又称相同原则（principle of identity），是指被请求引渡人的行为，必须是请求引渡国和被请求引渡国双方法律都认定犯罪并可以起诉的行为，反之，则不能引渡。

双重归罪原则是指被请求引渡的罪犯或犯罪嫌疑人，依请求国和被请求国的法律都构成犯罪，应受其引渡国的刑罚制裁。

参考双语例句：

Nevertheless, the Committee regrets the lack of an explicit reference in the State party’s legislation to the possibility of extradition of persons who committed offences addressed in the Optional Protocol and that extradition is subject to the criterion of double criminality.

然而， 委员会感到遗憾的是，缔约国立法未明确阐明，是否可引渡犯有《任择议定书》 所列罪行的人，而且引渡必须符合双重犯罪原则。

However, there were other countries where double criminality did not apply (e.g., Iraq) or did not apply with respect to certain crimes such as torture (e.g., Cameroon), genocide, terrorism, piracy, crimes against humanity, war crimes, ecocide, the production or proliferation of weapons of mass destruction and the application of prohibited methods of war (e.g., Armenia, Slovenia), financing of terrorism and money-laundering (e.g., Tunisia).

但在其他国家，双重犯罪的原则 不适用 (如伊拉克)，或不适用于某些特定犯罪，如酷刑(如喀麦隆)，灭绝种族罪、恐怖主义、海盗罪、危害人类罪、战争罪、生态灭绝、制造或扩散大规模毁灭性武器 及使用被禁止的战争方法(如亚美尼亚、斯洛文尼亚)、资助恐怖主义和洗钱(如突尼斯)。

Speakers identified existing challenges and difficulties in achieving effective international cooperation in criminal matters, including differences between legal systems, especially with regard to the requirement of double criminality and the discretionary or mandatory nature of prosecution for certain offences, often resulting in long waiting times when dealing with assistance requests.

发言者指出了在实现刑事事项方面有效国际合作中存在的挑战和困难，包括法律制度的差异，特别是在双重犯罪的要求方面以及对某些罪行的起诉是任择性的还是强制性的，从而往往导致在处理协助请求时要等很长的时间。