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Drug Offences Articles

How Do Police Use Mobile Phone Evidence in Possession with Intent to Supply Cases?

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Possession with intent to supply a controlled drug is a criminal offence under section 5(3) of the Misuse of Drugs Act 1971. The offence can be broken up into four parts:

  1. Possession
  2. with intent
  3. to supply
  4. a controlled drug

Possession – For the purposes of this offence, possession means to knowingly have drugs in your custody or under your control. Possession is not the same as ownership; a person who is looking after drugs for someone else still has possession of the drugs even though they do not own them.

A person can possess drugs even if they are not holding them at the time, so long as the drugs are under their control (e.g. if they are being stored back at the person’s address).

More than one person can have possession of a quantity of drugs at the same time if those persons all have control of the drugs. This is known as “joint possession”.

Possession requires knowledge that the drugs are under a person’s custody or control. For example, if a person puts on a friend’s coat which has a quantity of drugs in the pocket, but the person was unaware there were drugs in the pocket, then the person is not in possession of the drugs. The person lacks knowledge of the drugs and so they are not in possession of them.

Intent – The offence does not require an actual supply of drugs to take place. It is enough if the person who has possession of the drugs intends to supply the drugs to someone else in the future.

The offence does not require a plan to supply the drugs to a specific person at a specific time. Rather, a general intent to supply the drugs to some other person at some point in the future is enough.

Supply – Supply means to give the drugs to another person. Supply does not require money to exchange hands; it still amounts to supply if the drugs are given to another person free of charge.

It still amounts to supply even if a person gives the drugs back to their owner. If a person is looking after a quantity of drugs temporarily for a friend and then gives the drugs back to the friend at a later date, that would still amount to supply.

Controlled drugs – All controlled drugs are listed in the Schedule 2 of the Misuse of Drugs Act 1971. Controlled drugs are divided into three classes: A, B and C. Class A drugs offences carry the most severe penalties, then class B, then class C carry the lowest penalties.

The most common drugs which fall into class A are heroin and cocaine, but class A also includes drugs such as LSD, magic mushrooms, crystal meth, morphine and other opiates.

The most common drug which falls into class B is cannabis, but class B also includes drugs such as synthetic cannabinoids (like “Spice”) and ketamine.

Class C drugs tend to be weaker controlled drugs. They are often drugs that can be lawfully possessed if obtained from a doctor with a prescription, such as diazepam (also known as Valium).

The police have seized my phone, do I have to give them my pin code?

The simple answer is “no”, but there may be consequences if you don’t.

Normally, there is no requirement on someone who is arrested by the police to actively assist the police with their inquiries. This means that there is no general requirement for a person to hand over their PIN code if the police seize their mobile phone.

However, there is a specific police power under section 49 of the Regulation of Investigatory Powers Act 2000 which may apply in your case.

S.49 allows police to serve a notice on a person requiring that person to provide a “key” to any “protected information” which the police have seized. This could include requiring a person to hand over a PIN code to a mobile phone which has been seized by the police.

There are a number of limitations on the power under s.49. A police officer giving a s.49 notice must:

  • Get written permission to give a s.49 notice from a District Judge or Circuit Judge.
  • Be of at least the rank of Superintendent, or be a police officer who has been specifically authorised by an officer of at least the rank of Superintendent.
  • Reasonably believe that the person receiving the notice knows the PIN, that the notice is necessary for the purposes of preventing or detecting crime, and that the requirements in the notice are proportionate.

The s.49 notice itself must:

  • Be given to the recipient in writing, or otherwise in a manner where a record of the notice can be made (e.g. orally, during a tape recorded interview).
  • Describe the “protected information” (e.g. a PIN locked mobile phone) to which it relates.
  • Describe what information the recipient of the notice is required to provide (e.g. a PIN code), how the information should be provided (e.g. orally or in writing) and the time by which it must be provided.

If the above conditions are satisfied and a s.49 notice is served on a person, then it is a criminal offence for the person not to hand over the PIN.

I have private images on my phone, so I do not wish to give the police the pin code. What are the consequences?

If no s.49 notice has been served on you then there is no requirement to hand over your PIN. However, if you are subsequently brought to trial for possession with intent to supply a controlled drug, or any other offence, then the fact that you failed to disclose your PIN when asked to do so could be brought up as evidence at your trial that you must have had something to hide.

You also may not have your mobile phone returned to you by police if you fail to hand over your PIN when requested, as the police could argue that there could be important evidence or illicit material on the phone which they have not been able to examine.

Breaching the requirements of a s.49 notice is a crime. So, if a valid s.49 notice has been served on you requiring you to disclose your PIN and you fail to do so, you will likely have committed an offence.

The maximum sentence for that offence is two years’ imprisonment. Recent cases involving people failing to comply with s.49 notices issued in criminal investigations have resulted in sentences of around eight to 18 months’ imprisonment.

Can the police hack an iPhone?

Modern iPhones have very high levels of security. The information on them is encrypted so it is almost impossible to access the information stored in iPhones without the relevant PIN or password.

However, there are two potential ways that the police can try to “hack” into an iPhone if they don’t have a PIN or password.

The first is known as “brute-force” hacking. This involves trying to guess the PIN through a process of trial and error. The police have access to software which can cycle through every possible combination of numbers, trying each combination as a possible PIN.

This is a very slow process and will generally only be successful if the PIN is relatively simple (e.g. a four-digit PIN with repeated numbers). In order to speed up this process, the police often try to figure out more likely PIN possibilities from any personal information they have about the owner of the phone. For example, important dates such as the owner’s birthday or birthdays of family members, if they are known to the police, will likely be tried first as PINs.

The best way to protect against brute-force hacking is to use longer PINs or passwords (at least six digits) and not to use any obvious combinations of numbers.

Secondly, security or technology companies sometimes claim to have identified a weakness in iPhone security software. Some such companies have sold software to police and intelligence services which allegedly exploits these weaknesses so as to allow the user to “hack” iPhones.

However, these weaknesses are usually identified and corrected by Apple in future software updates. This means that the effectiveness of any such security software is short-lived. Also, such software is invariably extremely expensive. This means that most police forces do not have access to the software, and it is unlikely it would be utilised in a “straightforward” case of possession with intent to supply drugs due to the costs involved.

The end result is that, so long as you do not use a simple of obvious PIN or password for your iPhone, it is very unlikely that the police can hack into it.

How can the police prove a phone belongs to me?

The police will look at a range of factors and circumstances in order to attribute ownership or use of a particular mobile phone to a particular individual. This can include the following:

  • Where the phone was found – was it found on a particular person or at a particular address?
  • Subscriber details – is the phone number attributed to the mobile phone registered in anyone’s name?
  • Contact details –contacts stored on the phone may assist with attribution, e.g. if there is a number saved on the phone under the name “Mum” which the police know is your mother’s number, then that would support attributing the phone to you.
  • Call patterns – the pattern of calls and messages on the phone may assist with attribution, e.g. if the phone is mainly contacting other numbers which the police know belong to your friends and family, that would support attributing the phone to you.
  • Message content – the content of text messages, WhatsApp messages, Facebook messages etc can be downloaded from mobile phone handsets. Those messages may support attribution e.g. if they refer to the name of the phone user.
  • Social media/email accounts – numerous social media, email and other personal accounts can be linked to modern smart phones, which may support attribution of the phone to the owner of those accounts.
  • Cell-site – mobile phones connect to radio masts called “cell-sites” every time a call or text is made or received, or data is used. Phone companies keep a record of every phone number’s cell-site connections over the last 12 months. Police can use these records to determine the general location of a phone at a particular time by examining the location of the cell-site mast it connected to at that time. Cell-site evidence cannot place a phone at an exact location, but it can be used to prove that the phone was in the general area of a particular mast at a particular time, or to show general patterns of movement of the phone. Cell-site data can be used to support attributing a phone number to a person. For example, if a particular phone number is very frequently connecting to cell-sites near a person’s home, that would support attributing the phone number to that person.

 What information is held on my SIM card?

A SIM card stores the actual mobile phone number and details of the network provider which that number is linked to e.g. EE, Vodafone, O2.

Using this information, the police can contact the relevant network provider and request the registered details of the phone number’s user (known as “subscriber details”) and the call records and cell-site data of the phone number for the last 12 months.

If you have a pay monthly contract phone, or if you have a Pay As You Go phone and have registered the phone number in your name, then the subscriber details will include your name and other personal information which you provided to the network provider when you signed the contract or registered the SIM.

If you have a Pay As You Go phone and you have never registered the SIM in your name, then the subscriber details will most likely be empty.

A SIM card can also be used to store additional information such as phone contacts, text messages or call history. Whether or not a SIM card contains this kind of information will depend on the settings of the mobile phone handset in which the SIM card was used.

For instance, mobile phone handsets have settings options that allow received and sent text messages to be stored on the SIM card instead of, or in addition to, the handset’s internal memory. Similarly when saving new contacts, mobile phone handsets give the option of saving the contact to the handset itself or the SIM.

What information is held on my actual device?

The amount of information stored on a mobile phone handset depends on how it has been used. However, modern smartphones, including iPhones, can store a huge amount of personal information. This includes:

  • Text messages
  • Call history
  • Saved contacts
  • Social media accounts and usernames (if linked to the handset)
  • Email accounts (if linked to the handset)
  • WhatsApp messages (if WhatsApp is installed)
  • Facebook Messenger messages (if Facebook Messenger is installed)
  • Location data history
  • Photographs and videos taken on the device, or received via email of social media accounts
  • Web use history
  • Any information in cloud-based storage facilities which are linked to the handset

Police have specialist software which can download the stored information from a mobile phone handset and SIM card. The software may even be able to recover deleted messages and information, although the ability to retrieve deleted information is dependent on factors such as the length of time which has passed since the information was deleted.

What type of evidence are the police looking for on my phone? And how is it used in evidence against me?

If you have been arrested on suspicion of possession with intent to supply a controlled drug, the police will be looking for evidence that you have been involved in supplying drugs. This could include the following:


If a person has been arrested for suspected involvement in street dealing of a controlled drug – what might be called a “normal” investigation for possession with intent to supply – then the police will primarily be looking for evidence of drug dealing contained in messages on the person’s phone.

Police often look for “advertising messages”; messages sent to a large number of contacts advertising the type of drugs for sale.

They also look for incoming messages which appear to be from potential customers, such as messages asking if the phone user is “on” or “about”, or asking for quantities and types of drugs.

Such messages are often written in slang or code. For example, cocaine is sometimes advertised as “white” or just “w”. Police forces have specialist officers who are familiar with such slang who will analyse the messages on a phone.


The police may look for evidence of who owns a mobile phone. This is known as “attribution”. If an arrested person admits that a phone is theirs, then attribution is straightforward. However, if no one has admitted that a particular phone belongs to them, or if a person is found with a phone but denies it is theirs, then the police will look for evidence of attribution such as those categories of evidence listed above in the section on “How can the police prove a phone belongs to me?

Contacts and phone use

The police may look for evidence of who the user of a mobile phone has contacted. This may be relevant in larger drugs investigations, such as those involving alleged conspiracies to supply drugs.

For example, if the police have arrested several individuals who are suspected to be part of a conspiracy to supply drugs, then the police may look for evidence that the various individuals’ mobile phones have been in contact.

Isn’t evidence obtained from my phone hearsay and thus inadmissible in court?

Probably not.

Hearsay rules only apply to evidence that contains statements of fact or opinion. Much of the evidence which can be obtained from mobile phones does not fall into this category. For example, photos and other images, call history, cell-site data and contacts information will not normally be considered hearsay evidence because they contain no statement of facts or opinion.

The only category of evidence where hearsay is likely to arise as an issue are messages, such as texts and WhatsApp. Whether or not such evidence amounts to hearsay requires careful consideration, but often such evidence will not be hearsay. The Court of Appeal gave quite detailed guidance on how to approach the contents of messages and whether they amount to hearsay in the case of Twist [2011] 2 Cr App R 17.

If you are the person arrested, then any messages sent by you do not amount to hearsay, as hearsay rules do not apply to statements made by a defendant themselves.

Messages received to your phone from others may amount to hearsay evidence, but will do so only if the following conditions are met:

  1. the sender of the message is not a witness in the proceedings,
  2. the message contains a statement of fact or opinion which the prosecution wish to prove to be true, and
  • the sender of the message intended you to believe the statement or act upon it as if it were true.

This may sound quite complicated, and it is. Experienced lawyers and judges often have lengthy arguments and disagreements about whether a piece of evidence amounts to hearsay. However, it is worth noting that a lot of messages which the police rely on as evidence in drugs cases do not meet these criteria, and so do not amount to hearsay. For example, a message sent by a potential customer asking to be supplied a quantity of a controlled drug would not amount to hearsay because it is merely a question and contains no statement of fact or opinion. Such a message could still be relied on as evidence that the recipient of the message was involved in supplying drugs.

It is also worth noting that, even if a message does amount to hearsay, that does not necessarily mean it is inadmissible in court. The prosecution can apply to admit hearsay material as evidence in a trial if it meets certain criteria. The relevant criteria are contained in sections 114 and 116 of the Criminal Justice Act 2003. They include it being in the interests of justice to admit the material as evidence at the trial, and that the maker of the hearsay statement cannot be found despite all reasonably practicable efforts being made to find them.

What is the procedure the police must follow when downloading the contents of a phone?

There are some procedures that apply to all items seized by police as potential evidence. One such important principle is known as “continuity”. This means that a phone handset must be properly seized and exhibited by the police, and that a proper record must be kept of any dealings with the phone.

A phone handset will normally be exhibited by whichever police officer initially takes possession of a phone. That officer should give the phone an exhibit number, which is normally the police officer’s initials followed by a number. The process of seizing and exhibiting the phone should then be recorded in writing, usually in a witness statement.

The police must then keep a paper trail of every individual – whether a police officer or other person involved in the investigation – who subsequently handles the seized phone. Again, this is normally done by anyone who handles the phone writing a witness statement to describe when, where, how and why they handled the phone, and what they did with it afterwards.

In addition to the procedures that apply to all exhibits, there is also specific police guidance and procedures which apply to phones and other digital evidence. The Association of Chief Police Officers has issued a Good Practice Guide for Digital Evidence. This includes four key principles:

  1. No action taken when dealing with digital evidence should in any way alter the evidence which may subsequently be relied upon at court.
  2. Where a police officer or other investigator has to access the original electronic data, that person must be competent to do so and be able to give evidence explaining the relevance and the implications of their actions.
  • An audit trail of all dealings with the digital evidence should be created and preserved.
  1. The person in charge of the investigation has overall responsibility for ensuring that the law and these principles are followed.

Many investigating officers now have training in dealing with electronic evidence such as the material contained on phone handsets. In order to download the contents of a phone handset, an officer can use specialist software which automatically downloads a phone handset’s contents into an easily readable report with little additional action required by the officer.

What are the consequences if the police fail to comply with these procedures?

If the police fail to record properly the continuity of a seized phone handset, it may mean that any evidence arising from the handset is ruled inadmissible. This is likely only if the break in continuity is such that it is no longer clear whether the phone in question is the same one that was initially seized.

The consequences of other procedural failures depend on the severity of the failure. If the failure causes a significant prejudice to a defendant such that it would not be fair to rely on evidence obtained from the phone, then a judge could exclude the evidence at a subsequent trial. For example, if a police officer accidentally deleted the original data from a phone and it could not be examined by the defence, then any material which had been extracted from the phone by the police would likely be excluded as evidence.

In practice, these kinds of substantial errors are rare given that most of the work involved in extracting data from phones is automated, and so the possibility of human error is minimised.

I have been arrested and released under investigation; how long can the police keep my phone?

After a mobile phone has been seized, section 22 of the Police and Criminal Evidence Act 1984 allows the police to retain it for certain purposes, including:

  • for use as evidence at a trial for an offence, or
  • for forensic investigation in connection with an offence.

There is no specific limit on the length of time the police can retain a seized phone for these purposes. In practice, how long they retain it will depend on what was the reason for seizing it in the first place.

If you have been arrested on suspicion of involvement in the supply of drugs, and the phone was seized because the police believed it may contain evidence, then it will be retained for at least as long as it takes for them to carry out analysis of the phone and download its contents. Technical analysis of phones can take several months as there is a significant back-log with most police forces for carrying out analysis of electronic devices.

If, following analysis, it is confirmed that the phone does not contain any relevant evidence, then it should be returned to you. If, however, the police decide that the phone contains evidence relevant to a suspected offence with which you are charged, then the phone can be retained until the conclusion of any trial for that offence.

If you are convicted at that trial or plead guilty to an offence, then your phone may be forfeited under section 27 of the Misuse of Drugs Act 1971 and you may never get it back.

One consequence of the police power to retain a phone as suspected evidence is that, if you refuse to hand over your PIN, then your phone may never be returned as the police can argue that they have been unable to assess whether it contains anything of evidential value.

Author: Michael Goold – Garden Court Chambers


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