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Can you be stopped by a plainclothes policeman?

19 October 2010

I’ve posted before about the time I was stopped by police in an unmarked car.

I had just cycled through a zebra crossing, cutting in front of somebody crossing it on a bike. A car drew up alongside me and the lady in the passenger seat, wearing jeans and a t-shirt, told me off. I just ignored her. The car’s front grille then started flashing blue lights, I heard the siren and was pulled over. The same lady got out with her partner, both wearing Met police stab-proof vests.

My previous post explained why I don’t think I committed an offence at the time. The police just told me off, so maybe they agreed.

It made me wonder, though, what they could have done if I had committed an offence.


Police powers

When you’re cycling, a police officer can only require you to stop if he or she is in uniform. If they’re in uniform and tell you to stop, you’ll commit an offence if you don’t. (RTA s. 163(2), (3))

Similarly they can only give you a fixed penalty notice if they’re a constable in uniform. (RTOA s. 54)

They don’t have to be in uniform to arrest you. But they can only arrest you if you’re suspected of an offence, and it is necessary to arrest you for one of the following reasons (which I’ve summarised):

  • To enable your name and/or address to be ascertained (where they can’t ascertain this themselves, or have reasonable grounds for doubting whether what you’ve told them is accurate)
  • To protect against danger to you, other people or property
  • To prevent an obstruction of the highway
  • To enable the investigation of the offence, or prevent prosecution from being hindered by your disappearance.

(PACE s.24(5). There are other powers of arrest, like anti-terror provisions, but they’re for specific situations and it’s probably quite unlikely the police would try to use them in a normal traffic scenario.)

So the plainclothes police officers in an unmarked car couldn’t have required me to stop, and couldn’t have given me a FPN. They could have arrested me if they thought I had committed an offence, but only if one of the other conditions above was satisfied – for example if they’d asked my name and address, but had reasonable grounds for doubting whether I’d told the truth.

But what about when they put their stab-proof vests on – were they then in uniform?

What counts as being in uniform?

The law isn’t much help here. In one case a police officer administered a breath test to a driver (for which he had to be in uniform) while wearing his full uniform except for his hat. The Court said that he was in uniform despite the fact that the hat was missing. (Wallwork v Giles [1970] RTR 117)

The Court in the same case said that the purpose of the requirement that he be in uniform was so that he was easily identifiable as a police constable – nothing more. That would seem to suggest that so long as he has some police marking (for example a jacket) it would be enough.

On the other hand, in a later case the Court said that the purpose of the requirement is so that “the suspect has the satisfaction of knowing that the person asking for the breath specimen is a constable in uniform” – so you have to be able to see that he’s in uniform, not merely that he’s a constable. (Taylor v Baldwin [1976] RTR 265, 270)

So it looks like the words in uniform carry their ordinary meaning, but it’s not necessary for a constable to be wearing full uniform. It’s not clear cut, but it seems to me that a plainclothes policeman in a police stab-proof vest is probably not in uniform. If just wearing a stab-proof vest (over jeans and a t-shirt) was enough, the requirement that the constable has to be in uniform would essentially be meaningless.

Calling for backup

I’ve been asked what would happen if you’re stopped by a plainclothes policeman, but asked to wait so he can call for a constable in uniform to come and give you a fixed penalty notice.

On reflection, I think a FPN issued like this probably would be lawful. For the constable in uniform to issue the FPN, he has to have reason to believe that you’ve committed a fixed penalty offence. In this scenario, he probably would have sufficient reason to believe this on the basis that his plainclothes colleague would tell him. (RTOA s.54; Copeland v McPherson [1970] SLT 87, 89-90; Erskine v Hollin [1971] RTR 199, 203)

Bear in mind, though, that the plainclothes policeman can’t require you to stop (see above), so if he wanted to force you to wait for the constable in uniform to come along, he would have to arrest you. If you’re not posing any danger to any person or property, and are prepared to give your correct name and address, then it’s difficult to see what grounds he would have for arresting you – he wouldn’t be doing so to enable investigation of the offence, for example, but rather to enable a penalty to be given.

Of course that doesn’t necessarily mean he wouldn’t try. And you can judge for yourself the merits of debating cycle law with a plainclothes policeman who’s trying to arrest you. Practically speaking, if this happened your best bet would probably be to make sure you ask clearly for the reasons why you were being arrested – you could argue about the legal consequences later.


Photo by thardy1 from here

  1. Elanthius permalink
    19 October 2010 11:32

    This seems to say plain clothes police can arrest you if they suspect you of committing an offense and they want to get your address. So really they can stop you and at the very least make you listen to a lecture and take your address at any time if they can claim they suspected you committed an offense. Dangerous cycling perhaps?

    • 19 October 2010 12:00

      hi elanthius – i think they’re only likely to arrest you if they intend to take you to a police station/prosecute you for the offence. that’s presumably going to be far more hassle than giving you a fixed penalty notice, so is likely to be reserved for more serious offences (like dangerous cycling). but just jumping a red light, or a zebra crossing, is more likely to be the kind of situation where they wouldn’t bother to arrest/prosecute you; and if they don’t want to arrest you, there’s not a whole lot they can do if they’re not in uniform.

  2. manwithabike permalink
    20 October 2010 10:57

    Interesting read.

    As the same police who arrest you also have to scrape your remains off the road when you’ve jumped a red light I’m all for them stretching a point! Clearly the law exists to protect us from abuse of power by overbearing police officers, but it does rather sadden me when people like drink drivers, drivers without insurance and dangerous cyclists look for loopholes that let us get away with our anti-social habits.

    I write this having seen a rider this morning nearly get killed when she ignored a red light on the Marlebone Road and then shouted abuse at the hapless white van driver who narrowly spared her life.


    • 20 October 2010 11:41

      thanks liam – a fair point. personally i just think people need to know the rules and their rights – how they choose to behave, and what risks they choose to take, is up to them.

  3. Jacl permalink
    22 November 2010 19:53

    A plain clothes unit can arrest you as they suspect an offence has been committed and you have not stopped. Whilst you would not commit an offence of fail to stop, they would have been unable to ascertain your correct name and address and so their necessity test for arrest would be fulfilled. Quite how they will catch up with you I am not sure, perhaps when you are at a busy intersection you may be ‘oiked’ off of your conveyance?

    • 23 November 2010 09:58

      Hi Jack

      I think that’s broadly right. As I’ve mentioned above, the question is then whether they’d bother – probably only if you’d done something reasonably serious.


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