The police codes of practice state this:

‘2G When the person attends the police station voluntarily for interview by arrangement as in Note 2F above, their arrest on arrival at the station prior to interview would only be justified if:

• new information coming to light after the arrangements were made indicates that from that time, voluntary attendance ceased to be a practicable alternative and the person’s arrest became necessary; and

• it was not reasonably practicable for the person to be arrested before they attended the station.

If a person who attends the police station voluntarily to be interviewed decides to leave before the interview is complete, the police would at that point be entitled to consider whether their arrest was necessary to carry out the interview’.

To read the code, click here >

If you are arrested at a voluntary police interview, you may be able to sue the police for false imprisonment and assault.  That’s what happened in the case of The Commissioner of Police for the Metropolis v MR (2019).  MR had been had been in an on-off relationship with Ms A for about 15 months. In January 2010 Ms A contacted the police and made a complaint against MR.

She alleged that she had received a number of calls and texts from MR after ending their relationship, despite telling him to leave her alone.  She also alleged that once in October 2009, after a lot of calls from him, the intercom at her home had been buzzed for a long time.  The police carried out enquiries on the name given to them by Ms A, but couldn’t trace anyone with his name.  They did however have MR’s phone number – Ms A had given it to them.

A police constable from Walworth Police Station called MR on 11^th January and arrangements were made for him to go to Walworth Police Station.  According to MR, he arranged to go to the station on 13^th January, and then rearranged the appointment for the 12^th.  The police crime reporting system indicated he was to go on the 11^th, but the police didn’t suggest he was trying to get out of the appointment.  At 8am on 12^th January MR went to the police station voluntarily, where he waited in the foyer area.  At 8.30am a detective came and arrested him for harassment. MR said he was shocked and tried to explain he was willing to co-operate with the police.

He was interviewed by a different officer.  Whilst in custody, his fingerprints, photograph and DNA sample was taken.  After 6 hours and 50 mins he was released on bail.  The police kept hold of his phone. Ms A had also given the police her phone.  The police looked at the texts between them. MR had not been abusive or threatening.  The texts were friendly.  There was no clear request by Ms A for MR to leave her alone.

The police decided MR had not committed an offence, and on 2^nd February 2010 told him no further action would be taken.  MR claimed for false imprisonment and assault and won his trial at the Central London County Court.  The judge ruled his arrest was unlawful and awarded him damages of £2,750.  The judge accepted the detectives evidence that he believed arresting MR was necessary.  However, the judge ruled the officer’s belief in the need to arrest was not objectively justified.

The Commissioner of Police for the Metropolis appealed.  The High Court agreed with the judge in the County Court that there was no objective need to arrest MR given his voluntary attendance at the police station.  Mrs Justice Thornton dismissing the appeal said:

“Whether a person attending at a police station voluntarily for the purpose of assisting with an investigation needs to be arrested is fact specific.  The officer who has given no thought to alternatives to arrest is exposed to the risk of being found by a Court to have had objectively no reasonable grounds for his belief that arrest was necessary (Hayes at [34] & [40]).  The obvious alternative to arrest was to interview MR, establish his identity and require that he hand over his phone.  Any difficulties in this regard could have necessitated his arrest at that juncture, but not before.  Whilst acknowledging the operational experience and professionalism of the officer, I cannot see a rational basis for the arrest…”

The police officer in this case should have established MRs identity, interviewed him, and asked for his phone.  If the officer faced any difficulty doing this, he could have arrested him.  Each case is fact specific and it is for the officer who makes the arrest to establish that it is lawful.  The officer must suspect the person to be guilty of an offence and must have reasonable grounds for that suspicion.  In addition, the officer must be able to show why it was necessary to arrest the person: “There must be a rational reason for an officer to reject alternatives to arrest” (The Commissioner of Police for the Metropolis V MR)

This case highlights the importance for police officers to be able to rationally justify a decision to arrest.  Failure to do so opens exposes them to legal action for false imprisonment.