Prosecutorial policy and guidance

Published: 20 August 2013
  • Crown Prosecution Service policy and guidance clarifies which behaviours come under the scope of the criminal law.
  • The law applies to all serious sexual infections, although HIV is the only one mentioned by name.
  • For Scotland, the Crown Office and Procurator Fiscal Service has published similar guidance.

Crown Prosecution Service (CPS) policy1 and guidance2 was first published in March 2008, following extensive consultation. It has been updated twice since then, in June 2010 and again in July 2011. The policy and guidance have clarified many of the uncertainties created by two Appeal Court judgements3, 4 regarding under which circumstances the criminal law is likely to be used to prosecute the 'reckless' or 'intentional' transmission of sexual infection.

The policy and guidance cover “person-to-person transmission of a sexual infection that will have serious, perhaps life-threatening, consequences for the infected person's health”. Although not HIV-specific, HIV is the only sexual infection mentioned by name in the document.

The policy document explains the rationale for moving forward with a prosecution, how the CPS judges a case to be in the public interest and how it can be proven that a person recklessly or intentionally transmitted a sexual infection. It also outlines how they will support complainants through the court case.

The prosecutorial guidance also covers these areas, but in much greater detail, especially what is needed to prove reckless HIV transmission and issues concerning scientific and/or medical evidence.

Key points in the guidance relating to scientific and/or medical evidence and evidence of 'reckless' behaviour are outlined below.

Scientific and/or medical evidence

Phylogenetic analysis can only ever form part of the case against the accused, because it is not as precise as, for example, evidence of DNA matches. The CPS must also have a strong factual case supporting the allegation that the source of the infection was the accused before trying to prove that the accused was reckless.

Phylogenetic analysis can exclude the possibility of transmission between two persons where there is no relevant match between the two samples. However, it cannot prove that the accused didinfect the complainant – at best, any match would simply show that this was possible and additional factual evidence would be required.

Medical evidence used to support other factual evidence can include clinical records, including confirmation of diagnosis; evidence of symptoms; treatment; and viral load at the time of alleged offence.

In order to rule out that the complainant did not infect the accused or was not infected by a third party, enquiries will have to be made about the relevant sexual behaviour and relevant sexual history of the complainant. Not to rule out such a possibility would mean that there would be insufficient evidence to proceed.

Prosecutors will only accept a guilty plea once there is sufficient factual evidence that the source of the complainant’s infection is the accused.

Evidence of 'reckless' behaviour

Once sufficient factual evidence is obtained, prosecutors will look for evidence of recklessness – i.e. that the accused knew that they had HIV and were potentially infectious to others if they had unprotected sex.

The issue of recklessness only arises in circumstances where the complainant has not consented to the risk of acquiring HIV. If the accused had disclosed their HIV-positive status before unprotected sex, their sexual partner would be seen as having given consent to this risk.

Although disclosure is one way to obtain consent, the guidance notes that if the complainant has become aware of the specific risk of acquiring HIV from the accused through other means and nevertheless has unprotected sex, they are deemed to have consented.

It is not necessary for the prosecutor to prove that disclosure did not take place, or that informed consent to the specific risk of HIV infection was not given in some other way.

However, the accused may defend him or herself by demonstrating that disclosure of HIV status did take place, or that consent was otherwise given. It would be up to the jury to decide if this was a valid defence.

This applies in cases of reckless HIV transmission. If the allegation is of intentional HIV transmission, disclosure cannot be used as a defence.

To prove recklessness, prosecutors will need to prove that the accused not only knew they were living with HIV but also understood how the virus can be transmitted and which “safeguards” reduce risk. If it can be shown that they have been advised that an undetectable viral load is as effective a “safeguard” as the use of a condom in reducing risk, this would prove that they were not reckless even if transmission subsequently occurred. If the accused admits that they intended to infect their sexual partner, this is not sufficient on its own to meet the evidential test: other factual evidence will be required to prove intent.

NAT and THT have produced a leaflet for people with HIV explaining the guidance. ‘Prosecutions for HIV Transmission: A guide for people living with HIV in England and Wales’ is available on the NAT website.


The Crown Office and Procurator Fiscal Service (COPFS) published its prosecution policy on ‘Intentional or reckless sexual transmission of, or exposure, to infection’ in May 2012.5 Although not HIV specific, the policy outlines the circumstances in which a prosecution is likely to take place and helps to explain what constitutes a crime in relation to HIV transmission or exposure under Scots law.

Where possible, COPFS has sought to reconcile their policy and practice with CPS policy in England and Wales. However, due to the fact that HIV exposure as well as transmission can be a criminal offence, there are some differences.

The guidance notes that prosecutions for HIV exposure should only apply in exceptional circumstances. These circumstances should be limited to where a person can be shown to have undertaken a ‘flagrant course of conduct’, for example by having risky sex without disclosing their HIV status on many occasions and/or with a number of sexual partners. They may also apply where a person deliberately misleads their partner or conceals information from them about the risks. Exposure charges could also be made alongside a transmission charge to demonstrate a pattern of criminally reckless behaviour.

Usually consent is not considered to be a defence to a charge of assault or culpable and reckless conduct in Scots law. However, the guidance states that prosecutions will not take place if consent to the risk of HIV acquisition was fully informed and freely given. Consent would be considered to have been obtained if the person with HIV disclosed their HIV-positive status before unprotected sex and the complainant then agreed to unprotected sex, having understood the risks.

In summary, COPFS guidance states that prosecutions will be unlikely where the following circumstances apply:

  • The accused did not know that they were living with HIV.
  • The accused did not understand how HIV is transmitted.
  • The accused disclosed their HIV-positive status to the complainant(s).
  • The accused took reasonable steps to reduce the risk of transmission, for example, by using recommended precautions or avoiding higher risk acts.
  • The accused was receiving treatment and had been given medical advice that there was a low risk of transmission or that there was only a negligible risk of transmission in some situations or for certain sexual acts.

COPFS guidance states that prosecutions are more likely where the following circumstances apply:

  • The accused deliberately misled or concealed information from the complainant.
  • The accused did not attempt to reduce the risk of transmission, for example by failing to take prescribed medication or by failing to follow particular medical advice.
  • The complainant was particularly vulnerable in some way.
  • There is evidence that the accused had intentionally embarked on a course of flagrant conduct.

NAT, THT and HIV Scotland have produced a leaflet for people with HIV explaining the guidance. ‘Prosecutions for HIV & STI Transmission or Exposure: A guide for people living with HIV in Scotland’ is available at:

Criminal law and other STIs

In England and Wales, and in Scotland, police investigations and prosecutions are also possible, and have taken place, for the transmission of other sexually transmitted infections (STIs).

Although the criminal law has been used for other sexually transmitted infections much less frequently, in England there have been prosecutions for the reckless transmission of hepatitis B6, gonorrhoea7 and herpes8. The herpes case is currently being appealed and the outcome may impact future CPS policy and guidance as it relates to STIs.

In Scotland, there has been one prosecution of hepatitis C transmission; the person was prosecuted for HIV transmission at the same time.


  1. CPS Policy for prosecuting cases involving the intentional or reckless sexual transmission of infection. London. Available at: London, July 2011
  2. CPS Legal guidance: Intentional Or Reckless Sexual Transmission Of Infection. London. Available at:, July 2011
  3. England and Wales Court of Appeal R v Dica [2004]. EWCA Crim 1103 , 2004
  4. England and Wales Court of Appeal R v Konzani [2005]. EWCA Crim 706, 2005
  5. COPFS Sexual Transmission or Exposure to Infection - Prosecution Policy. Available at:, May 2012
  6. Mohanty K The first case of criminalization of transmission of hepatitis B in the UK: defendant sentenced to two years' imprisonment on the grounds of hepatitis B deoxyribonucleic acid sequencing. International Journal of STD and AIDS 20: 587-589, 2009
  7. Weait M UK: gonorrhoea prosecution “a dangerous development”. HIV Justice Network. Available at:, 23 April 2009
  8. Weait M Pass on herpes, go to jail? The Guardian. Available at:, 19 August 2011
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