Plebgate

I think that all you need to know can be encapsulated in these few lines from this BBC report:

'On Monday, the three officers said they had not planned to mislead the public.

...

However, in comments made after the meeting, one of the officers, Inspector MacKaill, claimed the former chief whip would not provide an account of the incident, and called for his resignation.

But Mr Mitchell had recorded the meeting, and a transcript showed that he apologised for swearing at the police officers and had denied using the word "plebs".'

An open and shut case? I'm sure the police officers will escape the full weight of the law, police officers do tend to.