Frequency of duplicate DNA fingerprints in the NDNAD

Paul Honigmann made this Freedom of Information request to National Policing Improvement Agency

The request was successful.

From: Paul Honigmann

22 July 2009

Dear Sir or Madam,

How many true duplicate DNA fingerprints are there in the NDNAD? I
refer not to the 13.7% of entries which are currently ascribed to
double-entries of the same individual ("replicates"), nor to the
identical fingerprints of twins and triplets, but actual, proven
cases of two or more non-identical-siblings having the same DNA
fingerprint. Ideally, I would appreciate the information in the
form "2,700 known duplicates, 113 triplicates" etc.

To aid you in tracking down this information - this data is
probably held by the Data Quality and Integrity Team (DQIT) who
work for the NDNAD's Custodian.

It may be that the information is available more readily through
the Match Reporting Database (MRDB) or Management Information
Database (MID) which were created specifically to get round
limitations in the NDNAD. These are anonymised, thus conveniently
fall outside the Data Protection Act.

The National DNA Database Annual Report 2004-5 (page 9) makes it
clear that when SGS+ was introduced as the DNA fingerprinting
scheme, it was not known what the occurrence of duplicates would be
and a large scale exercise was in progress to determine this at the
time. There was obviously concern at the time over the issue of
duplicates. With a database now in excess of 4.6 million
fingerprints, and simple statistical analysis, this information is
presumably now readily available.

I should mention that I originally requested this information from
the Home Office using whatdotheyknow.com's public online FOI
service, you can view the FOI request here:

http://www.whatdotheyknow.com/request/oc...

- the Home Office reply is there too, advising that they do not
hold the information and referring me to yourselves, as the
authority responsible for the NDNAD.

Yours faithfully,

Paul Honigmann

Link to this

From: NPIA FOI Team
National Policing Improvement Agency

23 July 2009

Dear Mr Honigmann

Thank you for your recent request for information, about the frequency of duplicate DNA fingerprints in the NDNAD, dated 22nd July 2009.

Your request was received on 22nd July 2009 and I am dealing with it under the terms of the Freedom of Information Act 2000.
We have logged your request which is receiving our attention. Your request reference number is 46851.

Please quote this reference number in any further correspondence or call relating to this enquiry.

Further information about the NPIA is routinely published on our website at www.npia.police.uk or through our publication scheme. If you require any
further assistance in connection with this request please contact us at our address below.

Regards

NPIA FOI TEAM
National Policing Improvement Agency

Email: [NPIA request email]
Website: www.npia.police.uk

show quoted sections

Link to this

From: NPIA FOI Team
National Policing Improvement Agency

18 August 2009

Dear Mr Honigmann,

Apologies, but it won't be possible to respond to your FOI request within the 20 working day time limit, however we are working towards replying to your FOI. We hope to have a response sent to you by the end of next week (28th Aug), if not before.

Again, apologies for the delay.

Regards,

Andy Woodgate
FOI Compliance Manager
National Policing Improvement Agency

Telephone: +44 (0)20 8358 5587
Web www.npia.police.uk

show quoted sections

Link to this

From: Paul Honigmann

18 August 2009

Dear Mr Woodgate,

re: request reference number 46851, 'Frequency of duplicate DNA
fingerprints in the NDNAD'.

Thank you for your update about the slight delay, I look forward to
a reply by the 28th August.

Yours sincerely,

Paul Honigmann

Link to this

From: NPIA FOI Team
National Policing Improvement Agency

26 August 2009

Attachment NRSB99 0111 090826 Final response 46851.pdf
75K Download View as HTML

Dear Mr Honigmann

Please find attached the NPIA's response to your request.

Regards

NPIA FOI TEAM
National Policing Improvement Agency

Email: [NPIA request email]
Website: www.npia.police.uk

Your right to complain

We take our responsibilities under the Freedom of Information Act seriously but, if you feel your request has not been properly handled or you are otherwise dissatisfied with the outcome of your request, you have the right to complain. We will investigate the matter and endeavour to reply within 3 – 6 weeks. You should write to:

David Horne
Director of Resources
National Policing Improvement Agency
10-18 Victoria Street
London
SW1H 0NN

E-mail: [email address]

If you are still dissatisfied following our internal review, you have the right, under section 50 of the Act, to complain directly to the Information Commissioner. Before considering your complaint, the Information Commissioner would normally expect you to have exhausted the complaints procedures provided by the NPIA. The Information Commissioner can be contacted at:

FOI Compliance Team (complaints)
Wycliffe House
Water Lane
Wilmslow
Cheshire SK9 5AF

Further information about the NPIA is routinely published on our website at www.npia.police.uk or through our publication scheme. If you require any further assistance in connection with this request please contact us at our address above.

*****************************************************************
Any opinions expressed in this email are those of the individual and not necessarily those of NPIA.
It is intended only for the person(s) to whom it is addressed and may contain privileged information.
Accordingly, the copying, dissemination or distribution of this message to any other person may constitute a breach of Civil or Criminal Law.
*****************************************************************

Link to this

From: Paul Honigmann

27 August 2009

Dear NPIA FOI Team,

thank you for the reply to my FOI request on the frequency of DNA
fingerprint duplicates, your ref 46851. I appreciate the time
you've taken to answer my query and the professional manner in
which you've handled it.

Yours sincerely,

Paul Honigmann

Link to this

From: Paul Honigmann

27 October 2009

Dear NPIA FOI Team,

With regards to my previous FOI request, your ref 46851 - frequency
of duplicates in the NDNAD.

You responded that only one full SGS+ non-identical-sibling
duplicate has been identified. I should have asked at the time,
what was the sample size? I.e, how may replicates were checked?

Yours sincerely,

Paul Honigmann

Link to this

From: NPIA FOI Team
National Policing Improvement Agency

28 October 2009

Dear Mr Honigmann

Thank you for your recent request for information, about frequency of duplicates in the NDNAD in relation to sample size, dated 27th October 2009.

Your request was received on 27th October 2009 and I am dealing with it under the terms of the Freedom of Information Act 2000.

We have logged your request which is receiving our attention. Your request reference number is 46941.

Please quote this reference number in any further correspondence or call relating to this enquiry.

Further information about the NPIA is routinely published on our website at www.npia.police.uk or through our publication scheme. If you require any
further assistance in connection with this request please contact us at our address below.

Regards

NPIA FOI TEAM
National Policing Improvement Agency

Email: [NPIA request email]
Website: www.npia.police.uk

show quoted sections

Link to this

From: NPIA FOI Team
National Policing Improvement Agency

3 November 2009

Dear Mr Honigmann,

Thank you query, I see that you have added this to your original request on the What do they know website. I have assumed that this is not a new FOI request (although we have logged it as one), you just require some additional information. I have taken your question to mean "how many profiles were the 'non-identical-sibling' samples compared against?".

Please let me know if I have interpreted this correctly, but also if you are submitting a new request.

Regards,

Andy Woodgate
IKS Advisor
National Policing Improvement Agency

Telephone: +44 (0)20 8358 5587
Web www.npia.police.uk

show quoted sections

Link to this

From: Paul Honigmann

3 November 2009

Dear NPIA FOI Team,

Your ref: 46851 (and 46941)

You asked for clarification: "I have assumed that this is not a new
FOI request (although we have logged it as one), you just require
some additional information. I have taken your question to mean
"how many profiles were the 'non-identical-sibling' samples
compared against?".

"Please let me know if I have interpreted this correctly"

Yes, you have interpreted this correctly. My latest request,
automatically assigned your reference number 46941, is a
continuation of the request originally assigned your reference
number 46851.

Yours sincerely,

Paul Honigmann

Link to this

From: NPIA FOI Team
National Policing Improvement Agency

25 November 2009

Attachment NRSB99 0111 091125 Final Response 46941.pdf
71K Download View as HTML

Dear Mr Honigmann

Please find attached the NPIA's response to your request.

Regards

NPIA FOI TEAM
National Policing Improvement Agency

Email: [NPIA request email]
Website: www.npia.police.uk

Your right to complain

We take our responsibilities under the Freedom of Information Act seriously but, if you feel your request has not been properly handled or you are otherwise dissatisfied with the outcome of your request, you have the right to complain. We will investigate the matter and endeavour to reply within 3 – 6 weeks. You should write to:

David Horne
Director of Resources
National Policing Improvement Agency
10-18 Victoria Street
London
SW1H 0NN

E-mail: [email address]

If you are still dissatisfied following our internal review, you have the right, under section 50 of the Act, to complain directly to the Information Commissioner. Before considering your complaint, the Information Commissioner would normally expect you to have exhausted the complaints procedures provided by the NPIA. The Information Commissioner can be contacted at:

FOI Compliance Team (complaints)
Wycliffe House
Water Lane
Wilmslow
Cheshire SK9 5AF

Further information about the NPIA is routinely published on our website at www.npia.police.uk or through our publication scheme. If you require any further assistance in connection with this request please contact us at our address above.

*****************************************************************
Any opinions expressed in this email are those of the individual and not necessarily those of NPIA.
It is intended only for the person(s) to whom it is addressed and may contain privileged information.
Accordingly, the copying, dissemination or distribution of this message to any other person may constitute a breach of Civil or Criminal Law.
*****************************************************************

Link to this

From: Paul Honigmann

25 November 2009

Dear NPIA FOI Team,

Your Reference: 46941

Dear Sir or Madam,

Thank you for your response of 25th Nov. Unfortunately I now
realise that my query can be read in more than one way, and you
have not answered the question as I intended it to be understood.
Please allow me to clarify:

When I asked "what was the sample size", I meant, not: "how many
matches were there to THIS particular duplicate" but: "how many
replicates have been checked to see if they are actually more than
one person, rather than simply double-entries of the same person".

Perhaps it would help if I laid out what I'm trying to determine.
Basically, it is not clear to me that the oft-stated statistic of
"one in a billion" is based on fact and I'm trying to reassure
myself that it is realistic. It seems to have been plucked out of
the air as a "best guess" based on assumptions of independent
markers according to the 2004-05 NDNAD report p.9, which refers to
a "large exercise currently in progress" to confirm this which
never seems to have been completed (according to your reply
Reference: 46851 dated 26 Aug 2009). Thereafter the statistic
appears to have been unquestioned: perhaps when responsibility for
the NDNAD passed to a new body (NPIA) any concerns over the
statistical integrity it is founded on were lost in the transfer.
So, another way to cross check this is to determine if any of the
13% of replicates in the NDNAD are, in fact, different people
rather than simply double-entries of repeat offenders etc. You
would expect that if the chances of duplicates were truly 1 in a
billion, there would be about 16,000 duplicates in the NDNAD (note
these are true duplicates, different human beings with identical
SGM+ fingerprints, not replicates). This may seem unintuitively
high, but google "Birthday Paradox" and you'll see why they were
concerned on p.9 of the 2004-05 report.

So, simply tabulating the number of replicates in the DQIT's weekly
report, or stating this year's total of replicates in the annual
NDNAD report, tells us little. The replicates need to be physically
checked by, say, the DQIT to find out if any are different people.
Checking 747,000 replicates is obviously unfeasible, but I'm hoping
SOME such checking has been done. For example, an alert could be
automatically generated to the DQIT if the same full SGM+ profile
appears in 2 different police reports in the same week. The 2004-05
report page 25 mentions that [someone] investigates if the names
for a given profile are different. THIS is the sample size I am
enquiring about. How many replicates have been checked to confirm
they are just the same person?

If this is in any way unclear, I would be happy to clarify further.

Yours sincerely,

Paul Honigmann

Link to this

From: NPIA FOI Team
National Policing Improvement Agency

26 November 2009

Dear Mr Honigmann

Thank you for your recent request for information, about Frequency of duplicate DNA fingerprints in the NDNAD, dated 25th November 2009.

Your request was received on 25th November 2009 and I am dealing with it under the terms of the Freedom of Information Act 2000.

We have logged your request which is receiving our attention. Your request reference number is 46983.

Please quote this reference number in any further correspondence or call relating to this enquiry.

Further information about the NPIA is routinely published on our website at www.npia.police.uk or through our publication scheme. If you require any
further assistance in connection with this request please contact us at our address below.

Regards

NPIA FOI TEAM
National Policing Improvement Agency

Email: [NPIA request email]
Website: www.npia.police.uk

show quoted sections

Link to this

From: NPIA FOI Team
National Policing Improvement Agency

11 January 2010

Dear Mr Honigmann

I am contacting you with regards to your FOI request 46983.

Please be aware that your request is still being dealt with by the respondents in the appropriate department and the consultation process with the 3rd parties involved is taking longer than we anticipated we expect to hear something back regarding your response by the end of this week.

We apologise for the delay and any inconvenience this may cause and we will keep you informed of the status of your request.

Regards

NPIA FOI TEAM
National Policing Improvement Agency

Email: [NPIA request email]
Website: www.npia.police.uk

*****************************************************************
Any opinions expressed in this email are those of the individual and not necessarily those of NPIA.
It is intended only for the person(s) to whom it is addressed and may contain privileged information.
Accordingly, the copying, dissemination or distribution of this message to any other person may constitute a breach of Civil or Criminal Law.
*****************************************************************

Link to this

From: Paul Honigmann

11 January 2010

Dear NPIA FOI Team,

re: FOI request 46983.

Thank you for keeping me updated on the delays to this enquiry. I
appreciate that the Christmas break and exceptional weather
conditions are disrupting peoples' normal work schedules; and that
the request is asking you to trace information which may not be
straightforward to collate in retrospect, as the record systems may
not have been designed to collate this kind of information.

Yours sincerely,

Paul Honigmann

Link to this

From: NPIA FOI Team
National Policing Improvement Agency

19 January 2010

Dear Mr Honigmann,

Regarding your request (our 46983).

Again, apologies for the delay and many thanks for your patience. I am hoping to have a response to you by the end of next week, I will keep you updated if there are going to be any changes.

Regards,

Andy Woodgate
IKS Advisor
National Policing Improvement Agency

Telephone: +44 (0)20 8358 5587
Web www.npia.police.uk

show quoted sections

Link to this

From: NPIA FOI Team
National Policing Improvement Agency

25 January 2010

Attachment NRSB999 0111 100125 Final response 46983.pdf
94K Download View as HTML

Dear Mr Honigmann

Please find attached the NPIA's response to your request.

Regards

NPIA FOI TEAM
National Policing Improvement Agency

Email: [NPIA request email]
Website: www.npia.police.uk

Your right to complain

We take our responsibilities under the Freedom of Information Act seriously but, if you feel your request has not been properly handled or you are otherwise dissatisfied with the outcome of your request, you have the right to complain. We will investigate the matter and endeavour to reply within 3 – 6 weeks. You should write to:

David Horne
Director of Resources
National Policing Improvement Agency
10-18 Victoria Street
London
SW1H 0NN

E-mail: [email address]

If you are still dissatisfied following our internal review, you have the right, under section 50 of the Act, to complain directly to the Information Commissioner. Before considering your complaint, the Information Commissioner would normally expect you to have exhausted the complaints procedures provided by the NPIA. The Information Commissioner can be contacted at:

FOI Compliance Team (complaints)
Wycliffe House
Water Lane
Wilmslow
Cheshire SK9 5AF

Further information about the NPIA is routinely published on our website at www.npia.police.uk or through our publication scheme. If you require any further assistance in connection with this request please contact us at our address above.

*****************************************************************
Any opinions expressed in this email are those of the individual and not necessarily those of NPIA.
It is intended only for the person(s) to whom it is addressed and may contain privileged information.
Accordingly, the copying, dissemination or distribution of this message to any other person may constitute a breach of Civil or Criminal Law.
*****************************************************************

Link to this

From: Paul Honigmann

31 January 2010

Your ref: 46851

Dear NPIA FOI Team,

thank you for the response to my query. You have explained that
there are two _confirmed_ cases of duplicate SGM+ DNA profiles
known to the NPIA after investigating 7165 replicates.

Interestingly your point 8 could be interpreted to mean that there
are, additionally, almost 1900 pairs of matches for which you offer
no explanation, ie:

7165 - (2x1092 confirmed from twins) - (3x3 confirmed from
triplets) - (1183 confirmed from false ID's etc) - (2x2 known
actual duplicates) = 3785 unexplained replicates, or 1892.5 pairs.

I think this could be worth further enquiry. It may simply be that
the DQIT team has not yet had time to check out the remaining
replicates thoroughly, or I have misinterpreted your point 8.
Perhaps they have
been determined to differ at STR's outside the usual SGM+ profile.
However, I think that this is best followed up in a separate FOI
request as you have, strictly speaking, answered my original query
concerning how many _proven_ duplicate profiles there are on the
NDNAD, and how many replicates have been checked to see if they are
real duplicates. I would like to close this FOI request now, or
your response time metrics will look artificially bad - which would
be unfair as you and your colleagues have gone to considerable
trouble digging out this information.

Many thanks for your time and patience,

Yours sincerely,

Paul Honigmann

Link to this

From: NPIA FOI Team
National Policing Improvement Agency

1 February 2010

Dear Mr Honigmann

Thank you for your recent request for information, about duplicate DNA fingerprints in the NDNAD, dated 31st January 2010.

Your request was received on 31st January 2010 and I am dealing with it under the terms of the Freedom of Information Act 2000.

We have logged your request which is receiving our attention. Your request reference number is 47058.

Please quote this reference number in any further correspondence or call relating to this enquiry.

Further information about the NPIA is routinely published on our website at www.npia.police.uk or through our publication scheme. If you require any
further assistance in connection with this request please contact us at our address below.

Regards

NPIA FOI TEAM
National Policing Improvement Agency

Email: [NPIA request email]
Website: www.npia.police.uk

show quoted sections

Link to this

From: NPIA FOI Team
National Policing Improvement Agency

26 February 2010

Attachment NRSB99 0111 100226 Final response 47058.pdf
77K Download View as HTML

Dear Mr Honigmann

Please find attached the NPIA's response to your request.

Regards

NPIA FOI TEAM
National Policing Improvement Agency

Email: [NPIA request email]
Website: www.npia.police.uk

Your right to complain

We take our responsibilities under the Freedom of Information Act seriously but, if you feel your request has not been properly handled or you are otherwise dissatisfied with the outcome of your request, you have the right to complain. We will investigate the matter and endeavour to reply within 3 – 6 weeks. You should write to:

David Horne
Director of Resources
National Policing Improvement Agency
10-18 Victoria Street
London
SW1H 0NN

E-mail: [email address]

If you are still dissatisfied following our internal review, you have the right, under section 50 of the Act, to complain directly to the Information Commissioner. Before considering your complaint, the Information Commissioner would normally expect you to have exhausted the complaints procedures provided by the NPIA. The Information Commissioner can be contacted at:

FOI Compliance Team (complaints)
Wycliffe House
Water Lane
Wilmslow
Cheshire
SK9 5AF

Further information about the NPIA is routinely published on our website at www.npia.police.uk or through our publication scheme. If you require any further assistance in connection with this request please contact us at our address above.

*****************************************************************
Any opinions expressed in this email are those of the individual and not necessarily those of NPIA.
It is intended only for the person(s) to whom it is addressed and may contain privileged information.
Accordingly, the copying, dissemination or distribution of this message to any other person may constitute a breach of Civil or Criminal Law.
*****************************************************************

Link to this

From: NPIA FOI Team
National Policing Improvement Agency

26 February 2010

Dear Mr Honigmann

Please accept our apologies for the spelling error in your name in your response as this has just been picked up.

Regards

NPIA FOI TEAM
National Policing Improvement Agency

Email: [NPIA request email]
Website: www.npia.police.uk

*****************************************************************
Any opinions expressed in this email are those of the individual and not necessarily those of NPIA.
It is intended only for the person(s) to whom it is addressed and may contain privileged information.
Accordingly, the copying, dissemination or distribution of this message to any other person may constitute a breach of Civil or Criminal Law.
*****************************************************************

Link to this

From: Paul Honigmann

27 February 2010

Dear NPIA FOI Team,

Thank you for your most recent reply to my FOI request, your ref
47058. I believe this answers my inquiry fully. No worries about
mis-spelling my name, I enjoy seeing imaginative variations.

Yours sincerely,

Paul Honigmann

Link to this

Things to do with this request

Anyone:
National Policing Improvement Agency only: