19-05-2008, 17:11:29
(This post was last modified: 19-05-2008, 17:12:17 by pinganilla bis.)
Quetza,
Ese artículo que cita es de 2005. Hace tiempo que ofrecí enviarles las recomendaciones vigentes de la Comisión de ADN de la Sociedad Internacional de Genética Forense (de 2006, ya puse alguna vez la cita y el resumen), que fueron aceptadas unánimemente (2007) por todos los miembros de ENFSI (European Network of Forensic Science Institutes), grupo en el que se integran los centros de genética forense de la Policía y de la Guardia Civil españolas, y con ciertas matizaciones más restrictivas por los grupos de Alemania y Reino Unido (ver texto a continuación). Si está interesado, mándeme un mail y se lo reenvío a vuelta de correo.
En ese resumen que aporta, de todas maneras, puede comprobar que existe una metodología bastante compleja para el estudio de las mezclas de ADN, que como ya le he dicho en varias ocasiones, no se aplicó en el caso de las ropas de Vicálvaro.
---
Forensic Science International: Genetics 1 (2007) 291–292
Interpretation of DNA mixtures—European consensus on
principles
With the improved sensitivity of modern DNA methods
coupled with the increased use of forensic genetics in crime
case investigations, the number of DNA mixtures composed of
full or partial DNA profiles from two or more contributors has
increased dramatically. The biostatistical interpretation of
mixed DNA profiles is a challenge—especially if DNA profiles
are incomplete. The DNA Commission of the International
Society for Forensic Genetics (ISFG) has offered recommendations
on DNA investigations for many years (please visit
http://www.isfg.org). In 2006, the DNA Commission published
recommendations on the interpretation on DNA mixtures in
crime case investigations [1]. Guidance was provided in
relation to the most frequent problems encountered with
mixtures. In this first paper, we noted that there exists some
diversity of practice throughout the world, although the general
principles could still be defined. Consequently, the DNA
Commission deliberately made broad recommendations to be
‘inclusive’ rather than ‘exclusive’, and were therefore flexible
enough to make local implementations possible also with
regard to existent differences in the national criminal justice
systems. At the same time, the authors recognised that ‘a period
of reflection’ was needed and invited a scientific discussion to
define the way forward. The comments we have received to date
are predominantly directed towards emphasis of alternative
practice (especially RMNE v. LR).
Unfortunately, the dual purposes of the communication
were not presented clearly in the publication of the ISFG
recommendations, and we have the impression that the
invitation to discuss further is being used in some countries
as an argument for a supposed lack of general consensus in the
international scientific community. This is, of course, a
misinterpretation, as it does not reflect the pattern of scientific
discourse.
In the interim, the recommendations of the DNA Commission
of the ISFG have been thoroughly discussed by at least four
scientific groups: we can now state that all the groups support
the principles of the ISFG recommendations.
The European DNA Profiling (EDNAP) Group of the
International Society for Forensic Genetics (http://www.isfg.
org/ednap/ednap.htm) has members from 20 European
laboratories actively contributing to forensic genetic research
as well as performing DNA investigations in crime cases.
During the last meeting 17–18 April in Krakow, Poland, the
members discussed the ISFG recommendations and decided
unanimously to support the ISFG recommendations.
The DNA Working Group of the European Network of
Forensic Science Institutes (ENFSI) (http://www.enfsi.org/
ewg/dnawg/) has members from approximately 40 European
laboratories that perform DNA investigations in crime cases.
During the last meeting 18–20 April in Krakow, Poland, Dr.
Peter Gill, The Forensic Science Service, UK, presented the
principles of the ISFG recommendations in details. The
recommendations were discussed and all representatives voted
unanimously for the following statement: ‘The general
principles described by the ISFG DNA commission recommendations
on mixture interpretation are accepted by the
ENFSI DNA working group’.
In Germany, the ‘Stain Commission’ (Spurenkommission—
gemeinsame Kommission der rechtsmedizinischen und
kriminaltechnischen Institute) has discussed the ISFG recommendations
and has published a response [2]. The German
guidelines follow the recommendations of the ISFG and
specify important implications e.g. defining and classifying
mixtures, giving specific guidance on the interpretation of
various types of DNA mixtures, clarifying the use of different
biostatistical approaches, and indicating pit falls in the
interpretation of DNA evidence—e.g. by stating what is not
acceptable.
In the UK, the Technical UK DNA Working Group has
discussed the ISFG recommendations and prepared a response
that addresses the ISFG recommendations in details [3]. The
group has formulated recommendations for DNA reporting in
the UK and submission of samples to the UK National DNA
database. The group took into account ‘local’ considerations,
court-going experiences and appeal court recommendations in
the UK. Thus, the UK response supplements the ISFG
recommendations by giving detailed guidance on specific
national issues.
We propose that the German paper and the UK response can
provide a model for other countries to follow in formulating
their local national recommendations. This seems to be the best
way forward to resolve the inevitable ‘finer’ points that may
have national relevance, but might be of limited international
relevance, and are therefore not covered by the ISFG DNA
commission document.
The ISFG recommendations on DNA mixtures were
formulated by international experts within the field and have
now been supported by a formal network of European and
national forensic genetic, scientific organisations. We consider
this to be sufficient evidence of a scientific consensus (or
general agreement) to support the basic principles concerning
the interpretation and formulation of the strength of evidence of
DNA results. We now encourage other regional and national
groups to establish further recommendations via local national
groups and to feed back to the DNACommission of the ISFG so
that they can be compiled and used to update and extend the
ISFG report at a later date.
Having clarified the status of the ISFG recommendations on
DNA mixtures, we would like to draw the attention to three very
important issues that must still be addressed at all levels, i.e. the
need for:
(1) clarification of working practices for the interpretation of
DNA profiles based on accreditation according to recognised
laboratory standards such as ISO 17025,
(2) education in the interpretation of the weight of the evidence
of complicated DNA profiles, and
(3) development of computer based expert systems that can
assist in the interpretation of complicated DNA profiles.
In relation to the formulation of ISO 17025 standards, the
Paternity Testing Commission of the ISFG provided a model by
publishing recommendations on genetic investigations in
paternity cases [4]. These recommendations clarified a number
of issues in relation to paternity testing. Similar clarifications
concerning genetic investigations in crime cases can include
guidance on the interpretation of DNA results.
In addition, the ISFG supports the educational challenges by
offering a two day educational workshop concerning the
interpretation of crime case DNA results before the 22nd
Congress of the IFSG 20–25 August 2007 in Copenhagen, and it
is the intention of the ISFG to support similar activities in the
future. These activities are, however, not enough. Regional and
national groups as well as laboratories must invest in continuous
education of the staff in the interpretation of DNA mixtures.
The ISFG recommendations and the supplementary information
that is emerging from the regional and national groups
has now made it possible for research and development groups
to develop IT-software for expert systems that can assist in the
interpretation of complicated DNA profiles.
The combination of international recommendations, clarification
of working practice by development of ISO standards,
education, and the availability of DNA interpretation expert
systems will offer valuable assistance to forensic genetic
laboratories to improve the quality of their reports that assess
the strength of DNA evidence in crime cases.
Ese artículo que cita es de 2005. Hace tiempo que ofrecí enviarles las recomendaciones vigentes de la Comisión de ADN de la Sociedad Internacional de Genética Forense (de 2006, ya puse alguna vez la cita y el resumen), que fueron aceptadas unánimemente (2007) por todos los miembros de ENFSI (European Network of Forensic Science Institutes), grupo en el que se integran los centros de genética forense de la Policía y de la Guardia Civil españolas, y con ciertas matizaciones más restrictivas por los grupos de Alemania y Reino Unido (ver texto a continuación). Si está interesado, mándeme un mail y se lo reenvío a vuelta de correo.
En ese resumen que aporta, de todas maneras, puede comprobar que existe una metodología bastante compleja para el estudio de las mezclas de ADN, que como ya le he dicho en varias ocasiones, no se aplicó en el caso de las ropas de Vicálvaro.
---
Forensic Science International: Genetics 1 (2007) 291–292
Interpretation of DNA mixtures—European consensus on
principles
With the improved sensitivity of modern DNA methods
coupled with the increased use of forensic genetics in crime
case investigations, the number of DNA mixtures composed of
full or partial DNA profiles from two or more contributors has
increased dramatically. The biostatistical interpretation of
mixed DNA profiles is a challenge—especially if DNA profiles
are incomplete. The DNA Commission of the International
Society for Forensic Genetics (ISFG) has offered recommendations
on DNA investigations for many years (please visit
http://www.isfg.org). In 2006, the DNA Commission published
recommendations on the interpretation on DNA mixtures in
crime case investigations [1]. Guidance was provided in
relation to the most frequent problems encountered with
mixtures. In this first paper, we noted that there exists some
diversity of practice throughout the world, although the general
principles could still be defined. Consequently, the DNA
Commission deliberately made broad recommendations to be
‘inclusive’ rather than ‘exclusive’, and were therefore flexible
enough to make local implementations possible also with
regard to existent differences in the national criminal justice
systems. At the same time, the authors recognised that ‘a period
of reflection’ was needed and invited a scientific discussion to
define the way forward. The comments we have received to date
are predominantly directed towards emphasis of alternative
practice (especially RMNE v. LR).
Unfortunately, the dual purposes of the communication
were not presented clearly in the publication of the ISFG
recommendations, and we have the impression that the
invitation to discuss further is being used in some countries
as an argument for a supposed lack of general consensus in the
international scientific community. This is, of course, a
misinterpretation, as it does not reflect the pattern of scientific
discourse.
In the interim, the recommendations of the DNA Commission
of the ISFG have been thoroughly discussed by at least four
scientific groups: we can now state that all the groups support
the principles of the ISFG recommendations.
The European DNA Profiling (EDNAP) Group of the
International Society for Forensic Genetics (http://www.isfg.
org/ednap/ednap.htm) has members from 20 European
laboratories actively contributing to forensic genetic research
as well as performing DNA investigations in crime cases.
During the last meeting 17–18 April in Krakow, Poland, the
members discussed the ISFG recommendations and decided
unanimously to support the ISFG recommendations.
The DNA Working Group of the European Network of
Forensic Science Institutes (ENFSI) (http://www.enfsi.org/
ewg/dnawg/) has members from approximately 40 European
laboratories that perform DNA investigations in crime cases.
During the last meeting 18–20 April in Krakow, Poland, Dr.
Peter Gill, The Forensic Science Service, UK, presented the
principles of the ISFG recommendations in details. The
recommendations were discussed and all representatives voted
unanimously for the following statement: ‘The general
principles described by the ISFG DNA commission recommendations
on mixture interpretation are accepted by the
ENFSI DNA working group’.
In Germany, the ‘Stain Commission’ (Spurenkommission—
gemeinsame Kommission der rechtsmedizinischen und
kriminaltechnischen Institute) has discussed the ISFG recommendations
and has published a response [2]. The German
guidelines follow the recommendations of the ISFG and
specify important implications e.g. defining and classifying
mixtures, giving specific guidance on the interpretation of
various types of DNA mixtures, clarifying the use of different
biostatistical approaches, and indicating pit falls in the
interpretation of DNA evidence—e.g. by stating what is not
acceptable.
In the UK, the Technical UK DNA Working Group has
discussed the ISFG recommendations and prepared a response
that addresses the ISFG recommendations in details [3]. The
group has formulated recommendations for DNA reporting in
the UK and submission of samples to the UK National DNA
database. The group took into account ‘local’ considerations,
court-going experiences and appeal court recommendations in
the UK. Thus, the UK response supplements the ISFG
recommendations by giving detailed guidance on specific
national issues.
We propose that the German paper and the UK response can
provide a model for other countries to follow in formulating
their local national recommendations. This seems to be the best
way forward to resolve the inevitable ‘finer’ points that may
have national relevance, but might be of limited international
relevance, and are therefore not covered by the ISFG DNA
commission document.
The ISFG recommendations on DNA mixtures were
formulated by international experts within the field and have
now been supported by a formal network of European and
national forensic genetic, scientific organisations. We consider
this to be sufficient evidence of a scientific consensus (or
general agreement) to support the basic principles concerning
the interpretation and formulation of the strength of evidence of
DNA results. We now encourage other regional and national
groups to establish further recommendations via local national
groups and to feed back to the DNACommission of the ISFG so
that they can be compiled and used to update and extend the
ISFG report at a later date.
Having clarified the status of the ISFG recommendations on
DNA mixtures, we would like to draw the attention to three very
important issues that must still be addressed at all levels, i.e. the
need for:
(1) clarification of working practices for the interpretation of
DNA profiles based on accreditation according to recognised
laboratory standards such as ISO 17025,
(2) education in the interpretation of the weight of the evidence
of complicated DNA profiles, and
(3) development of computer based expert systems that can
assist in the interpretation of complicated DNA profiles.
In relation to the formulation of ISO 17025 standards, the
Paternity Testing Commission of the ISFG provided a model by
publishing recommendations on genetic investigations in
paternity cases [4]. These recommendations clarified a number
of issues in relation to paternity testing. Similar clarifications
concerning genetic investigations in crime cases can include
guidance on the interpretation of DNA results.
In addition, the ISFG supports the educational challenges by
offering a two day educational workshop concerning the
interpretation of crime case DNA results before the 22nd
Congress of the IFSG 20–25 August 2007 in Copenhagen, and it
is the intention of the ISFG to support similar activities in the
future. These activities are, however, not enough. Regional and
national groups as well as laboratories must invest in continuous
education of the staff in the interpretation of DNA mixtures.
The ISFG recommendations and the supplementary information
that is emerging from the regional and national groups
has now made it possible for research and development groups
to develop IT-software for expert systems that can assist in the
interpretation of complicated DNA profiles.
The combination of international recommendations, clarification
of working practice by development of ISO standards,
education, and the availability of DNA interpretation expert
systems will offer valuable assistance to forensic genetic
laboratories to improve the quality of their reports that assess
the strength of DNA evidence in crime cases.