Making Do With Partial Matches:
DNA Intelligence and Criminal
Investigations in the United
Kingdom
Robin Williams
School of Applied Social Sciences
University of Durham UK
Recent and Current Studies
• 2000-2001: Participation Observation of Crime
Scene Examiners in One Police Division
• 2001-2002: Study of Management of Crime
Scene Examination in Seven Police Forces
• 2002-2004: Development and Police Uses of
National DNA Database
• 2004-2007: Study of forensic DNA Databasing
and Datasharing across European Union
Structure of Presentation
• The National DNA Database
• Two kinds of low stringency searches
– Loading, searching and investigating ‘partial profiles’
– Familial Searching
• Using familial search results in investigations:
contestation, negotiated arrangements and
continuing issues
• Concluding remarks on forensic DNA innovation
and database governance
The National DNA Database
• Established April 1995 as Police Intelligence Database
• ‘Active Criminal Population’ ‘All Active Offenders’
• 31st July 2004:
– 2,396,429 Criminal Justice profiles (10% are ‘duplicates’).
‘Suspect offenders, the great majority of known active UK
offenders’
– 227,010 Unmatched Crime Scene Profiles
• 3,409 matches in June 2004
• 134,965 matches since May 2001
Widening the Net
• Main UK Net widening through expanded powers to
retain samples and profiles taken from suspects on
arrest.
• Also increased crime scene sampling
• But
– Very strong external and internal pressure to improve
detection rates
– Duty to investigate under Criminal Procedures and
Investigations Act (1996)
• Routine Process: TIE
• Exceptions and Innovations: Centres of Expertise
Low Stringency Searches and the NDNAD
Two recurrent/developing practices:
– Automated and bespoke searching and reporting of
matches from incomplete (partial) profiles.
‘PARTIAL HITS’, ‘MULTIPLE HITS’
– Bespoke searching for partial matches (with some
mismatching alleles) between profiles. ‘FAMILIAL
SEARCHING’
• Different search methods and different
investigative issues.
Familial Searching on the NDNAD
(i)
• Basic assumptions
• Confined to ‘cold case reviews’ and ‘hard to
solve’ serious crime investigations
• By April 2004: 20 investigations, 5 identifications.
– Some highly publicised by FSS and Police Service
• 2002 Joseph Kappen – sufficient certainty to authorise
exhumation of dead suspect for offences in 1973
• 2003 Geoffrey Gafoor – cold case review following
miscarriage. Original offence 1988.
• 2004 Jason Ward – murder of Gladys Godfrey
• 2004 Craig Harman – death of truck driver.
Familial Searching (ii)
• NDNAD Search Trajectory
– First search on ‘rarest allele’ (many thousands of hits)
– Include more alleles and also limit search by geographical area or
by other ‘intelligence’ e.g. witness statements
– Obtain names of these partially matched individuals from Police
National Computer
– Agree list of names with SIO for further investigation
• Investigative Trajectory
– Choose ‘overt’ or covert’ approach to Trace, Interview and
Eliminate potential close relatives of individuals on NDNAD.
– If overt: approach profiled person to name close relatives. TIE
those named suspects
– If covert: obtain relevant names from other intelligence, TIE those
named suspects by ‘mass screen approach’
Overt Approach to Parent/Child of
Suspect
“Scientists investigating……have obtained a DNA profile.
The police believe that this profile will belong to the
offender. You will be aware that your DNA profile is
recorded on the National DNA Database. Your DNA
contains half of the characteristics of the DNA that was
recovered from exhibits in this case. As DNA
characteristics are inherited it follows that your
parent’s/child’s DNA may also contain these similarities.
We ask for your assistance in locating your parent/child
so that a sample can be taken from him/her and he/she
can be eliminated from this investigation.”
Overt Approach to Suspect
“Through forensic intelligence we have information
which leads us to believe that there may be
similarities between the DNA profile of the offender
and your DNA profile. This intelligence is based on
the fact that the DNA profile of your parent/child is on
the NDNAD. Their DNA contains half the
characteristics of the profile of interest. As DNA
characteristics are inherited it follows that your DNA
may also contain these similarities. Therefore we ask
for your assistance in providing a sample so that you
can be eliminated from the investigation.”
UK Debate on the ethics of familial
searching
• Between
– Human Genetics Commission, Information
Commissioner, Association of Chief Police
Officers, Home Office and Forensic Science
Service
• About
– Compliance with relevant UK legislation on
uses of the NDNAD?
– Even if compliant, is the practice a breach of
‘qualified’ privacy rights under ECHR?
European Convention on Human Rights
• Article 8(1) Everyone has the right to respect for his
private and family life, his home and his
correspondence
• Article 8(2) There shall be no interference by a public
authority with the exercise of this right except such as in
accordance with the law and is necessary in a
democratic society in the interests of national security,
public safety or the economic well-being of the country,
for the prevention of disorder or crime, for the protection
of the rights and freedoms of others
Current Negotiated Arrangement
• Differences ‘resolved’ in ACPO/FSS Agreement of
Understanding and ACPO Code of Practice
(‘restricted documents’)
• FSS ‘Hard to Access’ Service
– Narrow range of crimes; full profiles only
– Necessity for other ‘relevant intelligence’ for the ‘prioritisation of
potential relatives’
– High-level authorisation
– Family Liaison strategy
– Community Impact assessment
– Detailed policy file
Issues
• Database Searching
– possible problems arising from
– 2001 legislation on voluntary sample retention
– 2003 legislation on retention of all arrestee samples
• Investigative Strategies
– What can be legitimately expected of those
approached?
– Consequences of request surveillance
– False inclusions and exclusions
– Confidentiality and disclosure
Low Stringency Searching & Net
Widening: Summary Remarks
• Forensic DNA innovation, Database
Governance and Accountability
– ‘A repository of sensitive personal information such
as this must be managed in an open, ethical and
accountable manner to protect the civil rights of
those whose information is held’ (Police Science
and Technology Strategy 2004-2007
Incomplete/Partial Profiles on NDNAD
31st March 2003
• CJ Samples
– 73% are 10 locus (20 alleles) ‘Full Profile’
– 27% are 6 locus (12 alleles)
• Crime Scene Samples
– 70% are 10 locus (20 alleles) ‘Full Profile’
– 20% are 6 locus (12 alleles)
– 10% are between 8 and 11 alleles
• Partial crime scene profiles with fewer than 8 alleles
cannot be loaded but can be ‘challenged’ on an ‘oneoff’ basis. 1,394 such searches in 2002/2003)
NDNAD Partial Profile Hits and Criminal
Investigations
• Partial crime scene profiles may facilitate categorical
exclusions
• Partial crime scene profiles may match other crime scene
profiles
• Newly loaded profiles match existing six locus profiles
• Partial crime scene profiles may match varying numbers
of reference profiles
– Avon & Somerset LCN study: 495 samples
89 profiles: 31 profiles ‘loadable’; 58 ‘challengeable’.
42 single hits; 20 hits against 2-10 profiles; 2 hit against 50 or more