Merseyside Police has made an out-of-court payment to a law student who was arrested after giving money to a homeless man.
George Wilson, 20, from Wallasey, had left a club in Liverpool in the early hours of the morning in January last year when he saw a homeless man and gave him a £1 coin.
But he was stopped by officers who believed they'd witnessed a drugs deal and arrested under the Misuse of Drugs Act. And, as one officer confiscated Mr Wilson's phone, he accidentally set it to record audio.
Mr Wilson, who was at Liverpool John Moores University at the time, told the officers he was a law student.
"Look, buddy, if I lock you up for being drunk and disorderly, because that's what you are being, you won't be a student of the law any more," one replied.
"I'll take that off you. So shut your mouth and stop being stupid."
And when Mr Wilson protested that, far from being disorderly, he'd been polite and respectful, the officer retorted: "That's not how I'll write it up, pal."
The officer later denied that he was threatening to falsify a statement, and an internal investigation concluded that the words had been ambiguous.
"I felt let down by the police and felt victimised by them," Mr Wilson tells the Liverpool Echo.
"I felt it was a relief to settle the claim, although it wasn't all upheld, so I still feel in a way proper justice wasn't found."
Police officers are obliged to comply with both the law and their own codes of practice; if they don't, it may be possible to sue. The process is the same as when suing anybody else, with cases heard in the normal civil courts. Legal aid is usually available for those on low incomes; and for those that aren't, numerous solicitors will work on a no-win-no-fee basis.
Your case is unlikely to succeed unless you have firm evidence or witnesses, and individual police officers won't be punished unless you make a separate complaint through the Police Complaints Authority.
And be warned that it can take two or three years for a case to come to court, although the police, as in this case, often settle out of court.
Indeed, earlier this year, the same force paid out £13,000 compensation to a man who had been wrongly arrested - only to arrest him again when he cashed part of the payment.
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