He decided there was insufficient evidence to justify criminal proceedings.

他判定没有充分的证据提起刑事诉讼。

《柯林斯英汉双解大词典》

Our criminal procedure law modified in 1996 has absorbed the thought of the Acuused Innocencent until Proven Guilty, which provided Non Prosecution and Judgement of Insufficient Evidence.

我国1996年修订的《刑事诉讼法》部分吸纳了存疑有利于被告的思想，规定了存疑不起诉、证据不足的无罪判决制度。

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The Crown Prosecution Service has now decided there is insufficient evidence to press criminal charges.

BBC: Minister refuses to speculate on job

One of the allegations against Robert Coles was investigated in 1997, and an arrest was made, but there was insufficient evidence to justify criminal proceedings at that time.

BBC: Priests arrested in Eastbourne in sex abuse inquiry

Last month police and the Crown Prosecution Service decided there was insufficient evidence to make a criminal case against the peer over his expenses claims during his time as leader of Essex County Council and closed their files.

BBC: Lord Hanningfield