Human Identification Solutions (HIDS) ConferenceMadrid 2-4 March 2015

Needles in Haystacks- Finding DNA traces to test in

complex historic cases

Professor Angela Gallop

4 March 2015

My talk today

• Historic cases and additional challenges they present

• Five of the UK’s most complex and high profile cases and howthey were solved

• Lessons learned from each for thefuture

• Particularly in relation to finding DNA traces to test

• And ensuring quality and relevance of the results

Extra challenges with cold cases

• Finding ‘things’ to test• Nature and condition of ‘things’

when they are found• Discovering what original tests

covered and detail of results• Shortcomings in Continuity and

Integrity• Getting free enough rein • Explaining why evidence originally

missed

Scientific documentation

Admin

Cardiff prostitute – what happened

• Vicious knife attack on young prostitute in Cardiff in 1989• Over 50 stab cuts, slit throat and cut wrists• ‘Foreign’ blood identified at crime scene• Said to match a female witness• 1992 false confessions led to conviction of

The Cardiff Three• Released on Appeal - 2 years later• Successive subsequent attempts to obtain DNA profile

from remains of the ‘foreign’ blood all failed

Cardiff prostitute – how it was solved

• Developed full understanding of sequence of events from blood patterns etc

• Focused on the ‘foreign’ blood• Unearthed new samples to test• Obtained full DNA profile –

forming a pattern on and around the body• No match on DNA Database

but manual search identified 14 year old boy as of interest

• Profiled his family members untilfound an uncle whose DNA matched

Cardiff prostitute - lessons learnt

• Make sure you really understand the crime scene

• Be persistent in locating for items to test

• Be imaginative about what totest

• Don’t put things in the ‘too difficult’ box

• Leave unsolved case files in good order

Young black boy – what happened

• Young black boy stabbed in leg with broken bottlein 2000

• In stairwell of block of flats in London

• Suspect brothers arrested 5 days later

• No forensic evidence found

• 2002 failed prosecution of 4 others

• No forensic evidence on them either

• 2002 Metropolitan Police commissionedindependent review of its performance

Young black boy – how it was solved

• Re-examined items from all previous suspects• Revealed blood on clothes of

both suspect brothers• Including 9mm stain on trainer• DNA in blood matched boy’s• Textile fibre embedded in blood

matched his jumper fibres• Other fibre links found but risk

of cross contamination

Young black boy - lessons learned

• Don’t make assumptions about previous work• Even if conducted by well trained scientists

working in quality assured and accredited environment

• Don’t let DNA blind you to otherevidence

• Check for obvious potentialcontamination routes at an early stage

• Don’t get caught up in any blame gameabout previous investigations

Young mother– what happened

• Young mother stabbed to death on Wimbledon Common in front of young son in 1992

• Lower clothing pulled down to expose intimate areas of body

• 1993 suspect S. charged with murder• 1994 suspect S. cleared after ‘honey trap’exposed

Young mother – how it was solved

• Examined items from victim - included body ‘taping’ on which no DNA originally detected

• Re-testing revealed victim’s DNA and hint of male DNA• Developed new enhancement technique

to improve results• Combined with other DNA techniques• Identified serial rapist and murderer

– suspect N.• Further links involved:

– Paint matching N.’s tool box– Footwear mark at scene

Young mother - lessons learned

• Be watchful for ‘dogs that don’t bark’ • Consider ramifications for other

cases – Operation Cube• Develop new techniques when you

need to even if these take some time• Complete their validation at the time• Trust your common sense and

experiment

Coastal Path Murders – what happened

• Couple shot at close range on coastal path in 1989• Bodies hidden in undergrowth• 2006 suspicions emerge about convicted

serial thief and armed robber, suspect C.• And potential links with murder of two other people and

multiple rape/sexual assault at gunpoint• Clothing and jewellery in local hedgerows

Coastal Path Murders – how they were solved

• Started with unsuccessful search for ‘foreign’ DNA on victims, then switched to textile fibres

• Found matches between fibres on victims and glove in hedgerow

• Then myriad of other fibre links between victims, suspect C.’s home and hedgerow

• And then fibre links with the two other victims and sex assault cases

• Victim’s blood on gun linked to suspect C.

• Then victim’s blood on suspect C.’sshorts

• Then victim’s daughter’s blood on suspect C.’s shorts!!!

Summary of forensic evidence

Coastal Path - lessons learned

• Beware of DNA straightjackets• Other evidence can guide you to

DNA• And enrich your understanding of the

crime and a suspect’s likely involvement• Balance close working relationships with

police and independence• Accept truth is sometimes stranger than

fiction• Don’t be put off if prosecutors find

evidence ‘inconvenient’

Black teenager – what happened

• Young black teenager stabbed to death in London in 1993 by gang of white youths

• Suspects identified after 2 weeks• Failed private prosecution in 1996• Independent Police inquiry for IPCC• Public Inquiry in 1998/9 – Metropolitan Police described as

‘institutionally racist’• Continuing investigation including forensic science• 2004 Crown Prosecution Service says insufficient evidence

to prosecute• 2005 double jeopardy scrapped

Black teenager – how it was solved

• Noticed red fibres on victim’s clothing which could have come from own shirt

• Found 2 types of similar fibres on suspects D.and N.

• Then found 2 more fibre types on themmatching other items of victim’s clothing

• And then blood in packaging of suspect D.’sjacket containing 5th matching fibre type

• Then found blood on the jacket itself• Found hair matching victim’s on suspect N.’s

jeans• Investigated potential for results due to cross contamination

Summary of forensic evidence

Suspect N. Suspect D.

Black teenager - lessons learned

• Don’t make assumptions about loss of evidence with time

• Don’t focus just on outer clothing fortransferrable traces

• Take debris inside packaging veryseriously

• Recognise evidence can be missedhowever diligent and quality controlledthe search

• Focus investigations into potential for contamination to make them manageable

Investigating Historic Contamination

• Availability and Opportunity

• Use a separate scientist working independently

• Take each strand of evidence and

– Explore its history since seizure of the relevant item

– And the history of the potential source of evidence

– Work out the nature and number of transfer steps required for unwittingly transfer of the evidence

– And likelihood of each of these steps occurring

– To estimate overall likelihood of contamination as explanation for the evidence

• Sitting in court to listen to relevant evidence

Critical success factors• Challenge historic expectations

• Don’t make assumptions about previous work

• Always start at the crime scene – however long ago

• Be imaginative about searching for things to test

• Be tenacious about finding them

• If you find 1 type of evidence, there may well be others

• Beware of the ‘too difficult box’

• When things don’t stack up, find out why

• Recognise when you’re on to something and look deeper

• Keep inventing new techniques and approaches

• Make sure they are covered within your quality management system

• Recognise truth is sometimes stranger than fiction• Explore potential for alternative explanations involving contamination

“Those who cannot remember the past are condemned to repeat it”

George Santayana

Human Identification Solutions (HIDS) ConferenceMadrid 2-4 March 2015

Needles in Haystacks- Finding DNA traces to test in

complex historic cases

Professor Angela Gallop

4 March 2015

Speaker was provided travel and hotel support by Thermo Fisher Scientific for this presentation, but no remuneration.