Cold case review solves 30 year old murder

There has been quite a bit of adverse publicity recently surrounding the reliability of forensic science, including DNA (consider: the US review of forensic science; the use, or not, of LCN DNA in the UK; the execution of a Texas man for a murder for which he was later found not to be guilty) this is a nice example of how cold case review can be successful.  It also gives a hint of the number of people on the UK DNA database and the number of people who are on the database but do not have a criminal conviction.  The second article describes how DNA can be extracted from exhumed remains in order to obtain a sample for analysis.

“Evidence from murderer’s body were the key

18 September 2009, The Portsmouth News

Advances in forensic science helped police finally solve the 30-year mystery surrounding Teresa de Simone’s death.  The period of intense investigation came after Robert Hodgson – also known as Sean – was acquitted in the Court of Appeal in March after serving 27 years in prison for Miss de Simone’s rape and murder.

A full crime scene DNA profile of the 22-year-old Teresa’s murder in a pub car park was developed as part of a case review.  Experts at the Forensic Science Service were able to test samples taken from killer David Lace’s body after it was dramatically exhumed from Kingston Cemetery in New Road, Copnor, last month.  The News understands the rigorous scientific tests involved the grim process of taking samples of bone or teeth from Lace’s remains, sanding or airblasting them to remove any contamination and then painstakingly extracting the DNA to enable a profile to be created.  Lace’s profile was checked against samples taken from the original crime scene at the rear of the Tom Tackle pub in Commercial Road, Southampton.  Results showed there is a one-in-a-billion chance of Lace not being responsible for her death.  The profile also matched that of Lace’s sister held on the National DNA Database.

Detective Chief Inspector Phil McTavish, who lead the fresh investigation, said: ‘At the time (of the murder], all detectives had to go on was blood groups.  ‘Now we had the DNA profile, we could start the elimination process in line with the background research of the case papers we were reviewing at the same time.  ‘The Forensic Science Service looked across the DNA database to find a match. The database threw up 30,000 results.  A lot of people on the DNA database don’t have criminal records. It was a process where we used some focussed research to focus on the most likely matches.  We found a match with a sibling, a sister of his.   Combined with the evidence gathered on the case papers, we sought approval from the Ministry of Justice to exhume David Lace’s grave.’

Hampshire Constabulary is ‘fully satisfied’ that the person exhumed from Kingston Cemetery was David Lace and that his DNA profile is a complete match for that of the suspect.   DCI McTavish said: ‘A match probability of one-in-one-billion has been given which basically means that the chances of obtaining a similar match from a person selected at random is of the order of one-in-one-billion.   He added: ‘The DNA result together with a full file of evidence has been submitted to Mr Alistair Nisbet of the Crown Prosecution Service for review and it has been determined that, had David Lace been alive today then there is a realistic prospect that a jury would properly conclude that he raped and murdered Teresa de Simone on December 5, 1979.  ‘Accordingly, if he was alive, Mr Nisbet would authorise that David Lace would be charged and prosecution commenced.  As a consequence of this decision and, taken together with the outcome of the extensive investigations we have undertaken, we are satisfied that we have identified the man responsible for the murder and rape of Teresa de Simone and we are not seeking any other person in relation to this case.  Additionally, we are not currently linking David Lace to any other undetected serious crime.”

Science behind the revelations

EXHUMED Police at Kingston Cemetery where David Lace was buried
EXHUMED Police at Kingston Cemetery where David Lace was buried

Forensic scientists carried out days of painstaking work to extract and clean up samples from David Lace’s remains before they were ready to create a DNA profile.  Their task may have been even more difficult due to the decomposed state of Lace’s body, which was buried in Kingston Cemetery, New Road, Copnor, following his suicide almost 21 years ago. Experts at the Forensic Science Service in London created the profile which exactly matched evidence found at the original crime scene. The Service said they could not comment on specific cases. But Dr Colin Dark, major crimes specialist investigator for the Forensic Science Service, revealed: ‘The best sample to take from the remains of someone who has decomposed is from the teeth or femur (thigh bone). A lot will depend on the condition of the remains.  We will carry out specialist cleaning in a sterile environment to get rid of any contaminant, such as remaining tissue using, air pressure or sandblasting. In the case of the femur the bone is cut open to reveal the central part and we would usually take a section about one or two centimetres in length. We would then crumble or crush it to a mixture of bone marrow, blood and bone itself. We would then use specialist biochemicals which remove the DNA from the background bone and other material we have ground down. Once we get to the stage where we have extracted the DNA out of that central area it takes a matter of hours to get a profile. It can take anything up to five days to prepare the sample. With teeth it is quicker once we have got rid of any contamination from the remains. We can then saw the tooth in half and the pulp can be extracted from there. After that we can create the profile by looking at two different chromosome sites and the sex chromosome to identify the sex. It is then fed into a special machine to create the DNA profile.”

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