Help guide
DNA Evidence - Questions & Answers
Yes, DNA evidence can be crucial, but most often its not. We debunk common misconceptions about DNA evidence and sexually violence cases.
There are often many unanswered questions and misconceptions about what DNA evidence is and its role within legal cases where sexual violence is involved. Here we debunk some of those myths and talk facts about DNA evidence.
What is DNA?
DNA is a genetic code that is unique to every individual and can be found in hair or in bodily fluids like saliva, blood and semen. Samples can be taken from crime scenes or from someone’s body which can be sent off for testing to see if DNA can be found that does not match the person it was taken from. This can help police identify if someone else’s DNA is present where it shouldn’t be, and it can then be compared against the DNA of a suspect in a case, if they have a sample from them.
How can DNA be helpful in sexual offences cases?
There are cases in which DNA evidence is helpful, such as if the suspect is unknown, they may be able to be identified this way if their DNA is already within police records or if they come to the attention of the police later down the line for another crime. It can also be helpful if the perpetrator denies any physical or sexual contact with the survivor, and DNA evidence can help show that this isn’t true.
Is there a case without DNA?
Many TV shows and movies portray forensic tests as crucial in solving crimes and obtaining guilty verdicts in court. This is a common misconception and in reality, DNA evidence plays little to no part in the majority of sexual offence investigations.
In many cases, DNA evidence either isn’t available or isn’t helpful to the case, even if it is available. With no statute of limitations on sexually violent crimes in the UK, it is common that there may be a delay in reporting for a variety of reasons. These reasons can include the survivor trying to make sense of what has happened to them, trying to find information about their options, ensuring they have support in place, they were very young at the time, they may feel more psychologically resilient in the future and many more. The law takes this into account and overall, doesn’t put a time limit on reporting crimes of a sexual nature.
What this means forensically though is that there may be little to no DNA evidence to gather in these cases as DNA evidence can only be collected within a very short window of time after an offence has happened, usually within a few days.
Is DNA evidence the holy grail of prosecutions?
In some cases, DNA evidence can be pivotal, but these are the minority. These are the cases in which they may be able to identify an unknown perpetrator, or if a perpetrator is giving a different version of events such as denying any physical contact and DNA evidence can prove otherwise. However, in the vast majority of cases we see, the issue is about consent, rather than evidencing there was contact between the people involved.
What if the DNA evidence is of no help?
There are two elements to investigating a sexual offence. The first element is about proving or evidencing that sexual activity took place been the survivor and the suspect, which is where DNA can be helpful. The second element is about consent and whether the suspect reasonably believed the survivor was not consenting. This consent element is what most sexual offence investigations revolve around and DNA evidence cannot assist with this. This is because DNA cannot tell the difference between a consensual sexual act and a non-consensual act.
In cases where both parties agree that there was sexual activity, but the survivor says it was non-consensual and the suspect says it was consensual, DNA would not be considered as part of an investigation. Even if DNA evidence is available in these cases, it would only be helpful in proving something that both parties are in fact already agreeing on but is of no use when looking at establishing non-consent.
In cases like this, there are lots of other avenues that can be explored during an investigation to help prove the survivor’s account. This can involve things such as speaking to witnesses (this can be people the survivor may have spoken to about what happened, not necessarily someone who was there when it happened), looking at CCTV, looking at school records (if it happened when someone was young), looking at medical records, looking at text messages, all alongside the survivors own account.
How is DNA collected?
DNA evidence is best taken in a forensically secure environment, like your local SARC (Sexual Assault Referral Centre). The local adult SARC in Sussex is in Crawley and is called the Saturn Centre. Survivors can self-refer to their local SARC even if they have not yet decided if they would like to report to the police. The SARC can take samples and hold them for up to two years, as well as ensure survivors have the support in place that they may need, including referring onto specialist support services.
There are self-swab kits available, however any DNA collected by these would potentially be rejected by police or heavily challenged in court as it would be argued that there is a high chance of cross contamination or that the samples have not been taken properly. As explained above, these self-swab kits, like swabs taken at a SARC, can’t tell you who’s DNA has been found, only if there is any present.