DNA Briefing Doc

 How many innocent children are being added to the National DNA Database?

 This briefing estimates how many young people (aged 10 to 17) who were added to the National DNA Database (NDNAD) in 2006/07 had not committed an offence.

Q1. What is the law and when did it come into force?

Since April 2004, anyone aged ten or above who is arrested in England or Wales for a recordable offence[i] and taken to a police station will have their DNA and fingerprints taken without their (or their parents’) consent. The DNA samples are all kept permanently and the computerised DNA profiles are also kept permanently on the National DNA Database (NDNAD), even if the person arrested is never charged or is acquitted. The law was not fully implemented in 2004/05 but it has been now. We expect that young people added to the NDNAD in 2006/07 will include all those arrested for recordable offences in 2006/07, who had not already been arrested in 2005/06 or did not have cautions or convictions from previous years (i.e. who are not already on the Database).

Q2. How many 10 to 17 year olds are there in England and Wales?

The most recent estimate is that there are 5,486,000 young people aged 10 to 17 in England and Wales[ii].

Q3. How many 10-17 year-olds are arrested and how many of these have committed an offence?

The Home Office publishes figures on the number of arrests of 10-17 year-olds each year (there were 330,800 arrests of 10-17s in 2004/05[iii]), but this is not the same as the total number of young people arrested, as some will be arrested more than once in a given year. However, a rough estimate is that about 4% of 10-17s are arrested per year (based on Home Office survey data for 2004/05[iv]): this is 219,440 young people. About 2% of 10-17s are arrested ‘offenders’ and 2% arrested ‘non-offenders’ (also based on Home Office survey data for 2004/05[v]), i.e. there are about 109,720 of each.

Q4. How many 10-17 year-olds were newly arrested in 2006/07?

About 41% of juvenile offenders re-offend within 12 months (2004 figure from Home Office report on juvenile re-offending[vi]). This is 41%x 109,720= 44,985 re-offenders.

Assume that re-arrest of remaining arrested juveniles within 12 months is random (4% of non-re-offenders). This means that there are 4%x (219,440-44,985) = 6,978 additional re-arrests (of juveniles who were arrested in previous 12 months but did not re-offend).

Assume these rates stay roughly constant from year to year. Then, the number 10-17s arrested in a given year, who have not been arrested in the previous year = 219,440-44,985-6,978= 167, 477. This is 3% of 10s-17s.

Q5. How many 10-17 year-olds were added to the National DNA Database in 2006/07?

All of the newly arrested 10-17 year olds will have their DNA taken. A recent parliamentary question[vii] revealed that the percentage of 10-18s added to the National DNA Database (NDNAD) in 2006/07 was 2.9% and the percentage of 10s-15s added was 2.2%[viii]. If 2.9% of 10 to 17 year-olds were added to the National DNA Database in 2006/07, this would be about 160,000 10-17s. This is consistent with our estimate that 3% of 10-17 year olds were arrested in 2006/07 who had not already been arrested the previous year (Q4).

Q6. How many of these 10-17 year-olds have not committed an offence?

There are two ways to try to estimate this:

(i) About 109,720 10-17s arrested each year have not committed an offence (Q3). However, some of these young people will have been arrested before. About 8% of 10-25 year-old non-offenders in a given year have cautions, reprimands or final warnings from previous years, and about 2% have been arrested in the last 12 months (no figure is available for 10-17s).[ix] So about 10% (10,972) of these 10-17s will already be on the Database. This means that we can estimate that about 90%x109,720=98,748 of the 10-17s added to the Database have not committed an offence.

(ii) There were 85,467 young people who received their first pre-court or court disposal in 2005/06 (i.e. a reprimand, final warning, or a conviction in court)[x]. There is no figure yet for 2006/07 but it is probably about the same. However, some of these young people will have been arrested before but not convicted, so they will already be on the Database. About 8% of juvenile offenders have been arrested in the previous year[xi]. So, of those receiving their first disposal about 8% will already be on the Database and about 92% (78,629 young people) will not. In total there were about 160,000 10-17s added to the Database in 2006/07 (Q5). This means that about 160,000-78,629=81,371 of the 10-17s added to the Database have not committed an offence.

From these calculations we can conclude that between 81,000 and 99,000 innocent 10 to 17 year-olds were added to the National DNA Database in 2006/07.

Q7. How many innocent 10-17 year-olds are on the DNA Database in total?

At the end of 2005, there were about 741,600 DNA profiles on the NDNAD from people who were under 18 at the time of arrest. Of these, about 24,000 had no further action taken following their arrest.[xii] An unknown additional number will have been acquitted by a court[xiii]. Some of these innocent under-18s will now be adults, but more 10-17s will have been added between the end of 2005 and April 2006, when the 2005/06 calculations start. We can therefore estimate that there at least an additional 24,000 innocent under-18s on the DNA Database, whose DNA was taken prior to April 2006. In total this means that there are at least 81,000+24,000=105,000 innocent young people on the National DNA Database.

References and footnotes