Introduction to Data Analysis with R for Forensic Scientists (International Forensic Science and Investigation)

322 Pages·2010·1.78 MB·English

by  James Michael Curran

Introduction to
Data Analysis with R for
Forensic Scientists
88262_FM.indd 1 6/25/10 2:01:41 PM
I N T E R N AT I O N A L F O R E N S I C S C I E N C E A N D I N T E R N AT I O N A L F O R E N S I C S C I E NCE
I N V E S T I G AT I O N S E R I E S A N D I N V E S T I G AT I O N S E R I E S
Series Editor: Max Houck
Firearms, the Law and Forensic Ballistics Fingerprints and Other Ridge Skin
T A Warlow Impressions
ISBN 9780748404322 C Champod, C J Lennard, P Margot,
Introduction to
1996 and M Stoilovic
ISBN 9780415271752
Scientific Examination of Documents:
2004 Data Analysis with R for
methods and techniques,
2nd edition Firearms, the Law, and Forensic Ballistics,
Second Edition
D Ellen
Forensic Scientists
Tom Warlow
ISBN 9780748405800
ISBN 9780415316019
1997
2004
Forensic Investigation of Explosions
Forensic Computer Crime Investigation
A Beveridge Thomas A Johnson James Michael Curran
ISBN 9780748405657
ISBN 9780824724351
1998
2005
Forensic Examination of Human Hair
Analytical and Practical Aspects of
J Robertson
Drug Testing in Hair
ISBN 9780748405671 Pascal Kintz
1999 ISBN 9780849364501
Forensic Examination of Fibres, 2006
2nd edition Nonhuman DNA Typing: theory and
J Robertson and M Grieve casework applications
ISBN 9780748408160 Heather M Coyle
1999 ISBN 9780824725938
2007
Forensic Examination of Glass and Paint:
analysis and interpretation Chemical Analysis of Firearms,
B Caddy Ammunition, and Gunshot Residue
ISBN 9780748405794 James Smyth Wallace
2001 ISBN 9781420069662
2008
Forensic Speaker Identification
Forensic Science in Wildlife Investigations
P Rose
Adrian Linacre
ISBN 9780415271827
ISBN 9780849304101
2002
2009
Bitemark Evidence
Scientific Method: applications in failure
B J Dorion
investigation and forensic science
ISBN 9780824754143
Randall K. Noon
2004
ISBN 9781420092806
The Practice of Crime Scene 2009
Investigation
Forensic Epidemiology
J Horswell Steven A. Koehler and Peggy A. Brown
ISBN 9780748406098 ISBN 9781420063271
2004 2009
Fire Investigation Ethics and the Pracice of Forensic Science
N Nic Daéid Robin T Bowen Boca Raton London New York
ISBN 9780415248914 ISBN 9781420088939 CRC Press is an imprint of the
2004 2009 Taylor & Francis Group, an informa business
88262_FM.indd 2 6/25/10 2:01:41 PM
I N T E R N AT I O N A L F O R E N S I C S C I E N C E A N D I N T E R N AT I O N A L F O R E N S I C S C I E NCE
I N V E S T I G AT I O N S E R I E S A N D I N V E S T I G AT I O N S E R I E S
Series Editor: Max Houck
Firearms, the Law and Forensic Ballistics Fingerprints and Other Ridge Skin
T A Warlow Impressions
ISBN 9780748404322 C Champod, C J Lennard, P Margot,
Introduction to
1996 and M Stoilovic
ISBN 9780415271752
Scientific Examination of Documents:
2004 Data Analysis with R for
methods and techniques,
2nd edition Firearms, the Law, and Forensic Ballistics,
Second Edition
D Ellen
Forensic Scientists
Tom Warlow
ISBN 9780748405800
ISBN 9780415316019
1997
2004
Forensic Investigation of Explosions
Forensic Computer Crime Investigation
A Beveridge Thomas A Johnson James Michael Curran
ISBN 9780748405657
ISBN 9780824724351
1998
2005
Forensic Examination of Human Hair
Analytical and Practical Aspects of
J Robertson
Drug Testing in Hair
ISBN 9780748405671 Pascal Kintz
1999 ISBN 9780849364501
Forensic Examination of Fibres, 2006
2nd edition Nonhuman DNA Typing: theory and
J Robertson and M Grieve casework applications
ISBN 9780748408160 Heather M Coyle
1999 ISBN 9780824725938
2007
Forensic Examination of Glass and Paint:
analysis and interpretation Chemical Analysis of Firearms,
B Caddy Ammunition, and Gunshot Residue
ISBN 9780748405794 James Smyth Wallace
2001 ISBN 9781420069662
2008
Forensic Speaker Identification
Forensic Science in Wildlife Investigations
P Rose
Adrian Linacre
ISBN 9780415271827
ISBN 9780849304101
2002
2009
Bitemark Evidence
Scientific Method: applications in failure
B J Dorion
investigation and forensic science
ISBN 9780824754143
Randall K. Noon
2004
ISBN 9781420092806
The Practice of Crime Scene 2009
Investigation
Forensic Epidemiology
J Horswell Steven A. Koehler and Peggy A. Brown
ISBN 9780748406098 ISBN 9781420063271
2004 2009
Fire Investigation Ethics and the Pracice of Forensic Science
N Nic Daéid Robin T Bowen Boca Raton London New York
ISBN 9780415248914 ISBN 9781420088939 CRC Press is an imprint of the
2004 2009 Taylor & Francis Group, an informa business
88262_FM.indd 3 6/25/10 2:01:41 PM
CRC Press
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88262_FM.indd 4 6/25/10 2:01:42 PM
Dedication
This book is for Kevin Curran, Joseph Dickson, Vicky
Gavigan, Bronagh Murray, Ken Tapper, Margie
Tapper, Pat Tapper, Paul Tapper, Simon Tapper, and
Libby Weston. Gone but not forgotten.
v

About the author
JamesM.CurraniscurrentlyanAssociateProfessorofStatisticsintheDe-
partmentofStatisticsattheUniversityofAuckland(Auckland,NewZealand).
Dr. Curranisalsotheco-directoroftheNewZealandBioinformaticsInstitute
at the University of Auckland (www.bioinformatics.org.nz). His interests
includecomputerprogramming,computationalstatistics,dataanalysis,foren-
sic science, the design and analysis of experiments, and bioinformatics. Past
research includes the interpretation and evaluation of forensic glass evidence,
evaluation of forensic DNA evidence, and the effects of population substruc-
ture on DNA evidence.
Dr. Curran is the author of more than 70 scientific articles on the subject
of statistical evaluation of forensic evidence. He has lectured statistics at
the university level for 16 years and has been an invited speaker to many
international workshops and conferences. He also also testified in forensic
cases in the United States and Australia as an expert witness.
Dr. Curran is a Senior Consulting Forensic Scientist to the United King-
dom Forensic Science Service (FSS) where he has worked since 2001 with
the development team for the FSS-i3 software suite for DNA analysis. Dr.
Curran is responsible for Kwikmix-3, a mixture interpretation package, and
LoComatioN,whichisaninterpretationtoolforlowtemplateDNA.Dr. Cur-
ran has also written the computational core of SPURS3, a package for DNA
interpretation used in ESR, New Zealand.
When Dr. Curran is not at work he can be found on his road bike, in the
garden, or playing with his PS/3, Xbox, or numerous computers.
vii

Acknowledgments
Therearemanypeopletothankfortheirhelpandinputtothisbook. Firstly,
IwouldliketothankDavidFirthforhostingmeattheUniversityofWarwick
where about two thirds of the manuscript was written. Thanks go to the
University of Auckland and the UK Forensic Science Service for the financial
support that made this work possible.
Iwouldalsoliketothankthosepeoplewhoprovidedmewithdata: Rachel
Bennett,JohnBuckleton,SallyCoulson,TachaHicks-Champod,DavidLucy,
AngusNewton,RayPalmer,JillVintner,SimonWong,andGrzegorzZadora.
Thanks also to José Almirall, Rod Gullberg, and Abderrahmane Merzouki
who gave me data that I did not use in the end. I especially hope that all of
thepeoplewhogavemedatagetsomethingoutofthisbook. Scienceisabout
transparency and repeatability. Access to data from experiments is vital in
this respect, as it not only lets others see what you have done but also allows
them to repeat your statistical analysis.
Thanks to those people who have helped with proofreading and general
comments: Karin Curran, David Firth, Cedric Neumann, Kathy Ruggiero,
and Torben Tvedebrink.
Thanks to those people who have helped me in my career over the years:
ColinAitken,DavidBalding,MartinBill,JohnBuckleton,ChristopheCham-
pod, Ian Evett, Alan Lee, Roberto Puch-Solis, Alastair Scott, Chris Triggs,
Kevan Walsh, and Simon Walsh.
And finally thanks to my family and my friends who put up with me.
ix