Just imagine the situation when a possible crime accomplice has to prove his alibi.

试想一下，当一个可能犯罪共犯需要证明自己不在犯罪现场时情形。

Whether there is proof that the defendant was not on the crime spot is essential in proof of his innocence.

证明被告不在犯罪现场证据对证明他清白非常必要。

On the morning of the crime he can surely prove an alibi.

在犯罪发那天早上， 他肯定可以证明不在犯罪现场。

You can offer no defence, no alibi — only a mere assertion which would not deceive a babe! — that you are not guilty.

你不能提供任何辩护， 也不能提供不在犯罪现场证据——只是一个不会欺骗婴言！——你是无罪。

When Filch wasn't guarding the scene of the crime, he was skulking red-eyed through the corridors, lunging out at unsuspecting students and trying to put them in detention for things like " breathing loudly" and " looking happy."

费尔奇如果不在犯罪现场巡逻，便瞪着两只红通通眼睛，偷偷隐蔽在走廊里，然后突然扑向毫无防备学，千方百计找借口关他们禁闭，比如说他们“喘气声太大”，或“嘻皮笑脸”。