extenuating circumstances可使罪行减轻的情况;情有可原
extenuating circumstance减轻情节
under extenuating circumstances情有可原
extenuating and mitigating circumstances可谅解性
ADJ（形容词） If you say that there are extenuating circumstances for a bad situation or wrong action, you mean that there are reasons or factors that partly excuse it. 情有可原的 [正式][usu ADJ n]
The defendants decide to admit their guilt, but insist that there are extenuating circumstances.
被告们决定认罪，但坚称有情有可原的情节。