Police Retention of DNA

A briefing for Members of the Scottish Parliament

             February 2006	

The law in England and Wales now allows the police to take DNA samples routinely without consent from anyone arrested in connection with any recordable offence: including being drunk and disorderly, begging or taking part in an illegal demonstration. All DNA samples are kept permanently by the companies that analyse them, and the DNA profiles and personal data (such as name and ethnic group) are also kept permanently electronically on the National DNA Database (NDNAD), even if a person is never charged or is acquitted., No other country in the world keeps DNA profiles and samples from innocent people permanently.

Scotland has its own DNA Database, but around 3,500 DNA profiles from individuals and 300 DNA profiles from crime scenes are exported to the NDNAD in England every month. The law in Scotland currently requires DNA profiles taken from people who are not convicted to be deleted from the NDNAD. However, plans are currently underway to change this law, to bring Scotland into line with England and Wales. GeneWatch believes that before any decision is taken, an important debate is needed about how to balance the benefits of the National DNA Database in tackling crime against the threats to privacy and rights.

What is the National DNA Database?
The National DNA Database was established in 1995 and is now the largest DNA database in the world. It relies on the fact that DNA can be taken from any sample of human tissue left at the scene of a crime. DNA profiles (a string of numbers based on part of the chemical sequence of the DNA) can be obtained and stored on computer from both crime scene DNA and from individuals’ DNA (usually collected at a police station using a simple mouth swab). A match between an individual’s DNA profile and a crime scene DNA profile indicates a high probability that the individual was at the crime scene and is therefore useful in criminal investigations.  

The Scottish Executive is currently deciding whether to introduce measures to allow the permanent retention of DNA from people who are not convicted of a crime. The controversial proposals will probably be introduced via the Police, Public Order and Criminal Justice (Scotland) Bill before it completes committee scrutiny in March 

No other country in the world keeps DNA profiles and samples from innocent people permanently

However, a DNA match is not the same as a DNA detection (Box A) or a conviction. Matches often occur because a person has a legitimate reason to be at or near a crime scene and mistakes can also arise, as they do with fingerprints (for example, in the recent McKie case). Corroborating evidence is therefore always necessary to secure a conviction in court.

A DNA database is not required to provide evidence of guilt or innocence when there is a known group of suspects for a specific crime: a DNA sample can be taken from each individual (without consent on arrest, or with consent before arrest) and the DNA profile can be compared directly with a crime scene profile.  For the same reason, a database of individual DNA profiles is also unnecessary to exonerate an innocent person. The ‘added value’ of putting individuals on a database is only to introduce new suspects into a past or future investigation. The aim of putting more crime scene DNA profiles on the Database is to increase the number of crimes detected and the aim of entering and retaining more individuals’ DNA profiles on the Database is to increase the DNA detection rate  - see Box A. 

The Database is generally less useful for detecting violent or sexual crimes than volume crimes (such as car theft) because: 
•	the perpetrators of violent crimes are usually known to their victims so the Database is then unnecessary to identify a list of suspects; 
•	the DNA of the victim (for example, in a bloodstain) is usually much more relevant to establishing who committed a violent crime than the DNA of potential suspects; 
•	for rapes, the issue of whether the woman consented (which cannot be resolved by DNA) is more often disputed than the identity of the man involved.

The value of entering increasing numbers of DNA profiles from individuals on the Database (unrelated to the reason for arrest) is that it may allow investigation of a past crime to be re-opened, by identifying a new suspect. The purpose of retaining an individual’s DNA profile on a database is to treat them as a suspect for any future crime. This is arguably likely to be of most benefit when an individual has a record as a “career criminal” and is considered likely to re-offend (or, perhaps, to be deterred from re-offending by the retention of their profile). Although it is possible that a previously innocent person subsequently commits a crime and is identified because their DNA profile is already on the Database, it is the permanent retention of these profiles that is most controversial. 

Matches often occur because a person has a legitimate reason to be at or near a crime scene and mistakes can also arise

The purpose of retaining an individual’s DNA profile on a database is to treat them as suspects for any future crime

Box A: DNA matches and detections

DNA matches indicate that the DNA profile of an individual on the Database matches a DNA profile taken from a crime scene. Provided the samples have not been contaminated or mixed up and the DNA is not degraded (so that a full profile can be obtained) this indicates a very high probability (although not certainty) that the DNA at the crime scene came from that individual.

Detections are crimes that have been ‘cleared up’ by the police – usually by charging, cautioning or warning an individual. The overall detection rate is the number of detected crimes divided by the number of recorded crimes: this is the proportion of crimes that are detected in a given year (26% in 2004/05). On average, about half these detections lead to a conviction and half of these convictions involve a custodial sentence.

The DNA detection rate measures the proportion of crime scene DNA profiles which led to a detection (40% in 2004/05). This indicates that collecting DNA from a crime scene can increase the chance that a crime is detected (from 26% to 40%). However, the 40% DNA detection rate is largely determined by volume crimes (such as burglary). DNA detection rates have not been reported for violent or sexual crimes. 

The proportion of total crimes detected using DNA is much lower than the DNA detection rate, because crime scene DNA profiles are entered on the Database for less than 1% of all recorded crime. For example, in 2004/05 there were 5.6 million recorded crimes, of which 913,717 (16.2%) had a crime scene examination, leading to 49,723 crime scene DNA profiles being added to the Database. DNA profiles were therefore loaded from only 0.88% of crime scenes. As 40% of these were reported as detected, this implies that only 0.35% of crimes were detected using DNA. This figure overestimates the value of the Database, because only about half of these detections were new detections (i.e. the first link between the suspect and the scene of crime). 

What are the potential dangers of expanding the Database?
“I’m worried that it will scar my record for life. It might come up if I went for jobs, such as with children – not that I’ve been in trouble, but just that I’m known to the police.” Caitlin Bristow, aged 15, arrested in England following a counter-claim after reporting an assault. Never charged with any offence.

The National DNA Database is a useful tool in criminal investigations, but the permanent retention on it of everyone who has been arrested raises important concerns about privacy and rights, including:
•	the potential threat to ‘genetic privacy’ if information is revealed about health or family relationships, not just identity;

The National DNA Database is a useful tool in criminal investigations, but the permanent retention on it of everyone who has been arrested raises important concerns about privacy and rights

•	the creation of a permanent ‘list of suspects’ that could be misused by governments or made available to a much wider range of organisations in the future;
•	the exacerbation of discrimination in the criminal justice system. 

Some of these concerns have been highlighted by recent revelations in England and Wales that the Database now contains the DNA profiles of:
•	124,347 people who have been arrested and subsequently not been charged or cautioned with an offence;
•	24,000 juveniles (people under 18) who have never been charged, convicted or cautioned; 
•	more than a third of black men in the UK population.

GeneWatch UK believes that there are important changes that could be made to the Database to safeguard privacy and rights without compromising the use of DNA in fighting crime.1 However, none of these safeguards have yet been implemented. 

What are the benefits of expanding the Database?
 “Evaluation of the Programme has shown that the number of matches obtained from the Database (and the likelihood of identifying the person who committed the crime) is ‘driven’ primarily by the number of crime scene profiles loaded onto the Database”. The Home Office (2006), paragraph 32, p10.7

“It is arguable that the general retention of profiles from the un-convicted has not been shown to significantly enhance criminal intelligence or detection”. The Police Liaison Officer, Scottish DNA Database, 2005.

The National DNA Database is a useful tool in tackling some crimes, but it is important to be clear about the relative benefits and disadvantages of the three major changes that have taken place as part of the DNA Expansion Programme in England and Wales. These are:
•	A change in practice in 2000 that meant that the police started collecting much more DNA from scenes of volume crime (such as burglary and car theft);
•	A change in the law in 2001 that meant DNA profiles from people who had been charged, but were subsequently acquitted or not proceeded against, could be permanently retained. 

GeneWatch UK believes that there are important changes that could be made to the Database to safeguard privacy and rights without compromising the use of DNA in fighting crime

•	A change in the law in April 2003, which came into effect in April 2004, that meant DNA was collected on arrest rather than on charge and permanently retained.

Although the number of DNA detections has increased significantly since the DNA Expansion Programme began in 2000, the number of detections peaked in 2002/03 and then fell in 2004/05.7 The Home Office argues that this is because there were fewer crimes and therefore less crime scene DNA loaded, leading to fewer matches. However, this indicates that it is the number of crime scene DNA profiles (not individuals’ profiles) added to the Database – particularly the decision to collect DNA from scenes of volume crime -  that is largely determining its usefulness. In fact, the DNA detection rate (the number of detections per crime scene DNA profile – see Box A) has remained more or less constant for the last three years, despite the Database expanding from 2 million to 3 million individual profiles. The effectiveness of expanding the number of individual DNA profiles retained is therefore at best extremely questionable.

In addition, any benefit must be weighed against alternatives (such as employing more police officers) and the potential threats to privacy and human rights. For example, the Home Office has been unable to point to any prosecutions that have resulted from the highly controversial practice of permanently retaining the DNA of innocent children who have been arrested by the police. 

Why keep DNA samples permanently?
The DNA profiles held on the computer Database can be 
used to investigate who a person is related to (including non-paternity), but are unlikely to contain personal genetic information about health or other characteristics. However, the DNA samples which are stored in refrigerated warehouses, remain permanently linked to the Database and contain unlimited amounts of genetic information about individuals, increasing privacy concerns. Destroying individuals’ DNA samples after their profiles have been obtained would prevent them being used in future to reveal personal genetic information or be used for purposes other than identification (such as controversial genetic research). It would also cut the costs of storing all the samples. However, this safeguard is not part of the changes planned for Scotland, nor has the cost-effectiveness of storing samples permanently ever been assessed.

The effectiveness of expanding the number of individual DNA profiles retained is therefore at best extremely questionable

Destroying individuals’ DNA samples after their profiles have been obtained would prevent them being used in future to reveal personal genetic information and cut the costs of storing all the samples

Conclusions
Blanket permanent retention of all DNA samples and profiles, including from people never charged or convicted with any offence, poses unacceptable threats to privacy and rights and risks losing public trust in the police use of DNA. Rather than adopting the law passed in England, the Scottish Executive should ensure that alternatives are properly investigated and debated. This requires: 
•	independent research into the effectiveness of the DNA Database in tackling crime;
•	public debate about whose DNA profiles should be retained and for how long. 

The aim should be to develop a policy of time limits on the retention of DNA profiles which balances the need to detect crime with the need to protect privacy and human rights, and which maintains public trust and support. Any new legislation should also include additional safeguards to:
•	make the National DNA Database’s governing body more transparent and democratically accountable in Scotland;
•	ensure the destruction of individuals’ DNA samples once an investigation is complete, after the DNA profiles used for identification have been obtained; 
•	end the practice of allowing genetic research using the Database or samples.

References