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Maddie :Fingerprints and DNA

Investigation – Exchange of data

Translation based on the article by Tânia Laranjo/João Mira Godinho in today's Correio da Manhã

A Portuguese delegation of four persons, under the management of the Judicial Portuguese Police , travelled yesterday to the laboratory of Birmingham, in London, to cross information, for the first time, with the technicians that carried out the analyses to the vestiges gathered in the investigation to the disappearance of Madeleine McCann.

The unit, composed by a person in charge of the National Institute of Forensic medicine, two of the Laboratory of Scientific Police and an inspector of the Judicial Police of Portimão, reached London yesterday at around 12h15 and today a meeting is planned, at 11h, at police headquarters in Leicestershire. The homecoming is predicted for the end of the afternoon of tomorrow.

According to the CM, the team that yesterday traveled to London was going with precise indications. The three scientists aim is to get hold of the methodologies utilized by the referred London laboratory (FSS) in the analysis to the traces and try to anticipate all of the problems that can be raised by the arguidos - the parents of the missing infant to 3 of May in the Beach of the Light.

Francisco Corte - Real, representing the Administrative Council of the National Institute of Forensic medicine and the person in charge for the delegation of the Center of the INML, who was in charge of the first genetic examinations done still in Portugal will carry out a comparison study of the results found in the preliminary genetic tests in Portugal and what has been found in England.
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Still, according to the CM, this diligence is customary in processes that involve international collaboration assessing itself of fundamental importance for the inquiry of the Portuguese Judicial Police. For this reason one of the police officers will be present in all the meetings who pertains this role in the investigation, of decoding the scientific results and applying them to the criminal investigation.

PROCESS IS ENDING

The PJ still expects ending the investigation before the 3rd of January, the day that marks the eight months since Madeleine McCann disappeared.
.It is critical the understandings of the genetic findings as those are the key of an investigation that continues without obtaining the fundamental proof: Madeleine's corpse, without with difficulty it will be possible to explain how the child will have died.

In the absence of material proofs and lack of confessions of the arguidos, regarding what could have taken place the investigators are obliged to sustain the scientific proof, as the one that will be able to put really in question the theory of the parents - that remain on being the kidnapping theory, with the admission of the most varied hypotheses. Still, the team is expected to bring back to Portugal the last reports of the examinations that had not yet been send by the FSS.


TO AVOID ENGLISH CRITICISM

The decision of sending to England the biological findings gathered in the apartment and in the car used by the McCanns was made with intent by the Judicial Police.

It was not the question of not 'trusting' the results of the National Institute of Forensic medicine, which was responsible for the first battery of examinations, instead leaving in the hands of the Englishmen the possibility of checking the essential proofs.

The decision to send the biological evidence to England for analyses was as well a political move to prevent any form of criticism regarding the actions of the PJ, the en result could indicate, and indeed is indicative of the guilt of the parents.

At the same time, they had their mind toward the use of technological additional effectiveness of the laboratory, as it’s considered to be one of the most sophisticated of the World. The PJ intended to show also a sign of confidence to the authorities of the United Kingdom.

NOTES

ENGLISH LABORATORY APPLIES THE TECHNICIAN LOW COPY NUMBER

Low Copy Number, designates the technique used by the laboratory of Birmingham in the analysis of the biological tracks. This technique allows doing a genetic identification from evidences left on the scene of a crime in very small quantities.

BIOLOGICAL TESTS POPULARIZED BY TV SHOW CSI

The technique of Low Copy Number (see glossary bellow) was widely spread by the TV show ‘ CSI ‘ and represents a step above the lophoscopy (see glossary bellow) in the determination of an identity. It is a technique that it allows to identify a person from mere fluids.

ENGLAND AND THE UNITED STATES IN THE VANGUARD

The ideal on the stage of crime is to combine the gathering of samples for road lophoscopyand then the genetics, as happened in it Maddie’s case. The countries specialized in this combination of assemblage are England and the USA.


On DNA Profilling PDF
Application of Low Copy Number DNA Profiling by Forensic Science Service, Trident Court, Birmingham, UK

FingerPrints for Dummies on PDF
http://onin.com/fp/fingerprints_for_dummies_mar05.pdf

Glossary

Lophoscopy
The study of the development, the classification, and the identification
of the prints left by the papillary ridges of the skin.

Low Copy Number
Low copy number (LCN) DNA profiling is a technique sensitive enough to analyze just a few cells. When this kind of analysis is carried out, special considerations are needed to interpret the results. In particular, it is important to consider the implications of allele dropout and the possibility of contamination from a laboratory source. A rationale for interpreting LCN DNA is described.


More on FingerTips
:

Are fingerprints inherited... are they more similar between family members than between strangers?

The overall general flow or pattern (Level 1 detail) of friction ridges on human hands and feet is governed primarily by the height and position of the volar pads formed before birth.The formation of the volar pads is affected by inherited traits from the parents. High pads will form whorls, low pads arches, a medium height pad to one side a loop, etc. Thus twins or close relatives may have very similar ridge flow patterns (also called finger or palm print classification).

How long do fingerprints last on evidence?

Fingerprints on paper, cardboard and unfinished wood can last for up to forty years (per actual casework histories) unless exposed to water (and contaminate transfer prints can even then sometimes persist). Fingerprints on non-porous surfaces such as plastic, metal and glass can last for many years if not exposed to water and if left undisturbed.

Can a Fingerprint Expert determine if latent prints are "fresh" versus old?

Estimates about the age of latent prints are unreliable when the experts guessing have no idea what was on the fingers that touched a surface. Latent prints that develop "quickly, strongly or dark" are not necessarily consistent with having been "recently" deposited. Unless scientific analysis of latent print residue on evidence was completed before processing with powder or chemicals to visualize latent prints (which is an analysis seldom performed because latent prints tend to be invisible until processed), then the nature of the latent print residue deposited by the fingers or palms cannot be known (whether it was fried chicken oil, grease, natural secretions from the fingers, etc.). Circumstantial evidence such as information that an item was cleaned thoroughly with glass cleaner, soap and water, etc., could date latent prints on the item as not being older than the last thorough cleaning.

So what is normal if the police do come out and process your home or car for latent prints?

Unless it's a murder or rape, they usually only dust with powder for prints even though it leaves behind or destroys probably over 50% of the identifiable prints on glass, plastic and metal surfaces.

If the responding police are knowledgeable and have the time/money to give good service for your situation, they will probably use a strong flashlight and carefully look at shiny surfaces for fingerprints which can often be photographed without dusting... and using a strong flashlight they can also save time by not dusting a dresser top that has an undisturbed layer of house dust on it (it wasn't touched by the perpetrator). Good crime scene procedure at a burglary or rape also involves making the rooms dark and looking with a strong flashlight for footwear impressions in dust (especially behind a TV or VCR location on tile or vinyl floors). Such footwear impressions can be photographed, and then lifted with electrostatic dust lifters, gel lifters, or specially prepared (black) silicon rubber. Investigators should dust the doors, windows, dressers and other large, immovable surfaces after photographing identifiable prints they found with special lighting (such as bouncing the flashlight almost straight back into the camera from the shiny surface, or sometimes skimming the flashlight beam just across the surface). Yes, just looking with a flashlight and dusting leaves behind many of the identifiable latent prints... but, it is normally not reasonable to do tens of thousands of dollars damage to a home or business to get every possible latent fingerprint from a burglary. Such processing also takes days and the home/business cannot be occupied while the chemical processing is in progress.

More on DNA:

PRIMARY TRANSFER

Work was carried out to determine whether DNA profiles could be obtained from clothing; specifically,plain white T-shirts. After 8 hours wear, more of the wearer’s DNA was recovered from the front of the T-shirt than the back. Targeting the neck area maximised the chance of obtaining a useful result. In a series of simulated assaults, where one person grabbed the shoulder of another for a period of 30 seconds, mixed profiles were obtained from the grabbed area of the T-shirts. The “assailant” always contributed the major component to this mixture, regardless of his/her shedder type.

SECONDARY TRANSFER

Experiments were carried out to determine whether it was possible for individual A to transfer his DNA to individual B through contact, who could in turn transfer A’s DNA onto an object. We began with a scenario which was most likely to yield a result: a good DNA shedder (A) shook hands with a poor shedder (B),who then gripped a plastic tube for 10 seconds. The results from swabs of the tubes showed that on five separate occasions all of the good shedder’s profile was recovered, with none of the poor shedder’s alleles appearing.
The experiment was then repeated, but with the introduction of a delay of 30 minutes between the time of the handshake and the tube-holding. The results (Figure 2) indicated that although the poor shedder deposited some alleles, secondary transfer of the good shedder’s DNA still occurred. Further experiments are underway to determine the length of time between contact and tube-holding where no secondary transfer occurs, and to examine other types of transfer situations.

PERSISTENCE

Many factors may affect the persistence of low level DNA; time, temperature, humidity, etc. While it is unreasonable to test every combination of variables, some generic experiments have been undertaken and certain scenarios addressed.A time-study of the persistence of DNA is currently underway, where touched items have been stored at room temperature and tested to find out how much DNA can be recovered after certain periods of time.Figure 3 shows the results; full profiles were still recovered from surfaces touched by a good shedder even after 4 months, whereas a marked decrease in the recovery of the poor shedder’s DNA was observed.
An exchange of identical wrist-watches between certain shedder types was carried out to ascertain the period of time needed for the original wearer’s DNA profile to be replaced by that of the new wearer. Generally we found that a good shedder completely replaced the original wearer’s profile in 2-3 weeks,and after only a few days had become the major component of a mixture. An example of this is shown in Figure 4. In contrast, a poor shedder typically took around 2 weeks just to comprise the major component.

ENHANCED LATENT FINGER MARKS

The effect of various treatments used to enhance latent marks on either porous or non-porous surfaces was investigated. The finger marks used for these analyses were all deposited by the same individual on either acetate or paper for non-porous and porous surfaces respectively. The chemical treatments tested were CNA (in and out of a vacuum), aluminium powder, metal deposition, DFO, ninhydrin and physical developer. The effect of these chemicals on STR profiling was observed on freshly enhanced marks and marks that had been left for 100 days before DNA analysis was carried out. The mean results of replicate analyses carried out on single finger marks can be seen in Table 1. It was observed that overall, better recovery of DNA was possible from marks deposited on the non-porous surface. Marks enhanced with CNA, aluminium powder and metal deposition yielded full DNA profiles when DNA processing was carried within a week of treatment. However, recovery of DNA decreased when marks had been left in the enhanced state for 100 days. While some of the drop in DNA recovery can perhaps be accounted for by general degradation, the inability to recover any alleles from the marks treated with metal deposition suggests that some chemicals do radically effect DNA over time. A similar result was obtained from ninhydrin treated marks. Further observation of the results appears to indicate that the recovery of DNA from vacuum CNA treated marks increases over time post enhancement. However, this is unlikely to be the case. The reason for improved recovery may be due to two different pieces of vacuum CNA equipment being used for each sample set. Slight modifications to enhancement methods have been shown previously to improve recovery of DNA from marks in blood. An additional experiment using aluminium powder was also carried out. The relative levels of profile recovery from powdered marks in situ and from tape lifts of the marks were investigated. It was found that equal amounts of DNA could be recovered from the mark in situ and the lifted mark, both yielding approximately 70% of the fingerprint donors profile. This finding was important as it suggested that a mark could be lifted and preserved on tape for ridge detail analysis while the original deposit could be swabbed for DNA.


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