Israel Police, Division of Identification and Forensic Science. • Toolmarks and Materials Lab

Total Page:16

File Type:pdf, Size:1020Kb

Israel Police, Division of Identification and Forensic Science. • Toolmarks and Materials Lab Israel Police, Division of Identification and Forensic Science. • Toolmarks and Materials Lab. • Hadassah Academic College, Dept. of Computer Science • Hebrew University, Dept. of Statistics. The Israeli research team started 15 years ago, after a European “scale committee” was established. Vienna, 2003, Conclusion scale committee A small cut (1 mm) in the sole, how significant can it be? 97/3 point 1 Marks Working Group - Scale committee meeting Vienna - Finnish tests It is not the size… Changing angle 2 mm Is it a 1, 3 or 5 component? - it’s amount of information… Characterizing Shoeprints – From Class Characteristics To Accidental Marks Sarena Wiesner1 M.Sc., Yaron Shor1 M.Sc., Yoram Yekutieli2 Ph.D. 1) Toolmarks and materials lab. DIFS, Israel police 2) Hadassah Academic College, Dept. of Computer Science, Jerusalem. SAMSI workshop September 1st 2015 Technical Report TP-3211, Submitted to the U.S. Department of Justice, NIJ. 5 SAMSI September 1st, 2015 How do we Identify shoes? 6 SAMSI September 1st, 2015 Fingerprints vs. Shoeprints Fingerprints • Can’t be changed. • Consistent throughout whole life. • Typical pattern. • Minutiae consist of two basic types. • Spatial configuration of minutiae determines individuality. 7 SAMSI September 1st, 2015 Fingerprints vs. Shoeprints Shoeprints • Life span several years. • People own several pairs. • Changes with wear. • Unlimited patterns. • Unlimited accidental shapes. 8 SAMSI September 1st 2015 Connecting shoe to shoeprint Class characteristics • Pattern • Size • Wear Accidental characteristics • Cuts • Nicks • Tears • Foreign objects 9 SAMSI September 1st, 2015 Pattern Pattern is not brand! Reebok 10 SAMSI September 1st, 2015 Size 7.5 9 10.5 12 11 SAMSI September 1st, 2015 Wear Slight wear Intermediate wear Extreme wear 12 SAMSI September 1st, 2015 Accidental characteristics / Randomly acquired characteristic A feature …resulting from random events including, but not limited to: cuts, scratches, tears, holes, stone holds, abrasions and the acquisition of debris. The position, orientation, size and shape of these characteristics contribute to the uniqueness of a footwear outsole or tire tread. (SWGTREAD - Standard for Terminology Used for Forensic Footwear and Tire Impression Evidence) 13 SAMSI September 1st, 2015 Sampling process – Case work Suspect shoe Same accidentals Same Yes Test Same size appear on & wear? pattern? impressions print & shoe? Crime scene No No print Determine Exclusion Exclusion level of certainty 14 SAMSI September 1st, 2015 Creating test impressions 15 SAMSI September 1st, 2015 Sampling process – Case work Shoe Same accidentals Same Yes Test Same size appear on & wear? pattern? impressions print & shoe? Print No No Determine Exclusion Exclusion level of certainty 16 SAMSI September 1st, 2015 Comparison process 17 SAMSI September 1st, 2015 Comparison process • Very high quality prints – can see accidentals without shoe. • Most cases – See accidentals with overlaid test impression. • Very low quality prints – look at shoe to identify what to search for on print. 18 SAMSI September 1st, 2015 Sampling process – Case work Shoe Same accidentals Same Yes Test Same size appear on & wear? pattern? impressions print & shoe? Print No No Determine Exclusion Exclusion level of certainty 19 SAMSI September 1st, 2015 Determining level of certainty Identification Highly Probable Probable Possible Can’t be eliminated 20 NegativeSAMSI September 1st, 2015 From case work to research • Class characteristics not very discriminative. • Shoe-sole patterns change often. Focus on • Tearing behavior of accidentals! shoe-sole material similar for most shoes. 21 SAMSI September 1st, 2015 Database consisting shoes of various patterns A universal system for any possible pattern. Enables creating large database. Most shoe soles made of similar material, hence tear in similar way. Only contact areas can contain accidentals. Week points based on pattern. 22 SAMSI September 1st, 2015 Sampling process – Creating database of accidentals • Creating test impressions. • Scanning test impressions. • Semi-Automatically marking accidentals. • Finding shoe aligned coordinate system. 23 SAMSI September 1st, 2015 Scanning test impressions • 600 ppi. • Color. • JPG or TIFF files. 24 SAMSI September 1st, 2015 Semi-Automatically marking accidentals Marking the area Automatic marking Fine tuning the of the accidental of borders threshold Cleaning excess markings 25 SAMSI 2015st, 1September Three Criteria to evaluate an accidental Orientation 26 SAMSI September 1st, 2015 All the assumptions used are initial assumptions and further investigation into them is required! 27 SAMSI September 1st, 2015 The probability of having an accidental in a specific location Basic assumptions: We divide the test impression into grid cells and assume no more than one accidental in each cell. The size of each grid cell is the size of the error in locating the accidentals. Error ≈(5 mm) 2 = 0.25 cm2. The area of a shoe is 30x10 cm2 = 300 cm2 Assuming a uniform distribution of locations: p=1/1200 Average of 30 accidentals per shoe: P= 30 * (1/1200) = 1/40 28 SAMSI September 1st, 2015 Ref: Yoram Yekutieli, “Challenges in image analysis of shoeprints”, Tomorrow 9:45 The probability for a specific accidental orientation Basic assumptions: • The orientation of a shape is the angle of its major (longer) axis relative to the X axis of the shoe aligned coordinate system. • Error rate is determined by degree on elongation. • The distributions of orientations are largely uniform. 29 SAMSI September 1st, 2015 Ref: Yoram Yekutieli, “Challenges in image analysis of shoeprints”, Tomorrow 9:45 The probability of having an accidental with a specific shape Accidental shape compared against all the accidentals in the database. 30 SAMSI September 1st, 2015 Ref: Yoram Yekutieli, “Challenges in image analysis of shoeprints”, Tomorrow 9:45 The probability of having an accidental with a specific shape • For each comparison calculating its matching error. • Counting how many comparisons had a matching error value lower than the threshold. • Assuming 500 out of the 10,000 shapes lower than threshold: p(shape) = 500/10,000 = 1/20 31 SAMSI September 1st, 2015 Ref: Yoram Yekutieli, “Challenges in image analysis of shoeprints”, Tomorrow 9:45 Total probability of a single accidental Assuming independence of the parameters, for one accidental we have: p(accidental) = p(location) * p(orientation) * p(shape) = 1/40 * 1 / 18 * 1/6752 = 2.06e-7 32 SAMSI September 1st, 2015 Probability of a combination of accidentals We assume the orientations are independent. We assume that their shapes are independent. We assume the locations are independent. p(combination) = p(3 locations) * p(3 orientations) * p(3 shapes) And this is the same as ( p(single accidental) 3 ) * 3! Ref: Yoram Yekutieli, “Challenges in image analysis of shoeprints”, Tomorrow 9:45 33 SAMSI September 1st, 2015 The SESA system 34 SAMSI September 1st, 2015 Location - Checking the assumptions Is it justified to assume one accidental per cell? 35 SAMSI September 1st, 2015 Orientation Checking the assumptions How accurate is determining the orientation error based on the degree of elongation? 36 SAMSI September 1st, 2015 Shape - Checking the assumptions • Probability of rare accidentals limited by No. of accidentals in database. • Texture of shoe may interfere with correctly determining the shape contour. 37 SAMSI September 1st, 2015 Total probability Checking the assumptions • Is there any dependence between location, orientation and shape of an accidental? • Some accidentals are pattern element dependent! • Is there any dependence between different accidentals? 38 SAMSI September 1st, 2015 How does the working procedure affect the reliability of the database? Present comparison method Former comparison method 39 SAMSI September 1st, 2015 Test impression scanning method Former scanning method Present scanning method 40 SAMSI September 1st, 2015 Size of accidentals found with the new scanning and comparison method 41 SAMSI September 1st, 2015 From theory to reality 42 SAMSI September 1st, 2015 Real life shoeprints Test impression Print from crime scene 43 SAMSI September 1st, 2015 Real life accidentals • Partial shoeprint 44 SAMSI September 1st, 2015 Real life accidentals • Twisted prints 45 SAMSI September 1st, 2015 Real life accidentals • Partial accidental 46 SAMSI September 1st, 2015 Real life accidentals • Noise 47 SAMSI September 1st, 2015 Real life accidentals • Vague resemblance 48 SAMSI September 1st, 2015 Presenting the conclusion at court How do we translate the derived probabilities to an understandable and reliable conclusion? 49 SAMSI September 1st, 2015 ENFSI Marks conclusion scale Level Likelihood ratio Probability 1 Extremely strong support for 1,000,000 and above Identification proposition A 2 Very strong support for proposition 10,000 – 1,000,000 Very probably A Strong support for proposition A 1000 – 10,000 3 Moderately strong support for 100 – 1000 Probably proposition A Moderate support for proposition A 10 – 100 Weak support for proposition A 2 - 10 4 Inconclusive 1 Inconclusive 5 Weak support for proposition likely not (=not A) Moderate support for proposition Moderately strong support for proposition Strong support for proposition Very strong support for proposition 506 Elimination SAMSI Elimination 2015st, 1September Probability based on SESA system 51 SAMSI September 1st, 2015 Distribution of probabilities per levels of certainty Identification Very probably
Recommended publications
  • 1 Schlaglicht Israel Nr. 17/20 Aktuelles Aus Israelischen Tageszeitungen 1
    Schlaglicht Israel Nr. 17/20 Aktuelles aus israelischen Tageszeitungen 1.-15. Oktober Die Themen dieser Ausgabe 1. Gespräche zwischen Israel und Libanon ...................................................................................................................... 1 2. Demonstrationen gegen Netanyahu trotz Lockdown ................................................................................................... 3 3. Ultraorthodoxe im Abseits .............................................................................................................................................. 4 4. Medienquerschnitt ........................................................................................................................................................... 6 1. Gespräche zwischen Israel und Libanon Peace with Lebanon? Not so fast Seit Jahrzehnten zum ersten Mal treffen sich Vertre- Lebanon has never been a strong nation. (…) Saudi ter_innen aus Israel und dem Libanon zu Gesprä- Arabia (…) is now keeping its distance. Other Arab chen über ihre Meeresgrenze. Schauplatz ist der and Western nations have also turned their back on UN-Stützpunkt in Nakura im Südlibanon. Besonders Lebanon (…) French President Emmanuel Macron, umstritten ist ein Keil von 860 Quadratkilometern vor who felt obligated to come to Lebanon's aid, came der Küste beider Länder. Dort werden Gasfelder ver- back empty-handed when his plan to form a techno- mutet. Von der schweren Finanzkrise getroffen er- cratic government failed due to sectarian bickering. teilte
    [Show full text]
  • Archived Content Contenu Archivé
    ARCHIVED - Archiving Content ARCHIVÉE - Contenu archivé Archived Content Contenu archivé Information identified as archived is provided for L’information dont il est indiqué qu’elle est archivée reference, research or recordkeeping purposes. It est fournie à des fins de référence, de recherche is not subject to the Government of Canada Web ou de tenue de documents. Elle n’est pas Standards and has not been altered or updated assujettie aux normes Web du gouvernement du since it was archived. Please contact us to request Canada et elle n’a pas été modifiée ou mise à jour a format other than those available. depuis son archivage. Pour obtenir cette information dans un autre format, veuillez communiquer avec nous. This document is archival in nature and is intended Le présent document a une valeur archivistique et for those who wish to consult archival documents fait partie des documents d’archives rendus made available from the collection of Public Safety disponibles par Sécurité publique Canada à ceux Canada. qui souhaitent consulter ces documents issus de sa collection. Some of these documents are available in only one official language. Translation, to be provided Certains de ces documents ne sont disponibles by Public Safety Canada, is available upon que dans une langue officielle. Sécurité publique request. Canada fournira une traduction sur demande. Institute for Strategic International Studies ISIS - 2011 REPORT Emergency Readiness is Leadership Driven Institute for Strategic International Studies - ISIS 2011 Contents Membership … 3 Executive Summary … 4 Domestic Research Plan … 6 Global Research Plan … 7 International Field Studies - Interviews … 10 ISIS 2011 – Consolidation Of Research – What Canada Needs to Know … 11 ISIS 2011 - Themes … 12 1.
    [Show full text]
  • Top 17 Cases Version 4/27/2020, with Addendum
    2020 DNA Hit of the Year Top 17 Cases Version 4/27/2020, with Addendum * All addenda written by submitters. 1. Headless Outlaw’s Torso in Old Lava Tube Name of Submitter: Clark County Sheriff Bart May Location: Dubois, Idaho, U.S.A. Agency: Clark County Sheriff’s Office, Idaho Date of Crime: 1916 Date and Type of Hit: 2018-2019 (genetic genealogy to match with general family tree); 2018-2019 (familial match with living grandson to confirm family relationship) Executive Summary: 100-year-old unidentified human remains found in an old lava tube in 1979 leads to a cold case identification effort that lasts many years. However, his head was never located, baffling the FBI and other investigators for years. They could only establish that he was of European descent, with reddish-brown hair, and was about 40-years-old at the time of death. His arms, hand, and legs were found in 1991. Over the years, investigators enlisted the help of Idaho State University and its team of forensic genetic genealogists (anthropology students and staffers). This also included experts from the Smithsonian Institution and the FBI. Last year investigators further enlisted the help of the DNA Doe Project, hoping to use DNA and ancestral analysis to identify the man. Experts from Othram, a forensic DNA analysis company, analyzed samples taken from the remains, while a forensic genealogist from the DNA Doe Project worked with her colleagues to build a ‘genealogical tree’. The man’s DNA profile was then uploaded to various genetic genealogy DNA databases for relatives. This led to the man’s living 87-year-old grandson, whose sample was taken and tested to confirm a familial relationship.
    [Show full text]
  • TRAFFICKING in PERSONS 2020 COUNTRY PROFILE North Africa and the Middle East Table of Contents − Algeria −
    GLOBAL REPORT ON TRAFFICKING IN PERSONS 2020 COUNTRY PROFILE North Africa and the Middle East Table of Contents − Algeria − ...................................................................................................................................................... 3 − Bahrain − .................................................................................................................................................... 5 − Egypt − ........................................................................................................................................................ 8 − Iraq − ........................................................................................................................................................ 11 − Israel − ...................................................................................................................................................... 14 − Jordan − .................................................................................................................................................... 17 − The Kingdom of Saudi Arabia − ................................................................................................................ 18 − Kuwait − .................................................................................................................................................... 20 − Lebanon − ................................................................................................................................................
    [Show full text]
  • Private Security Companies and the Israeli Occupation Report by Who Profits Research Center January 2016 Cover Photo by Activestills
    Private Security Companies and the Israeli Occupation Report by Who Profits Research Center January 2016 Cover photo by ActiveStills. Private Security Companies and the Israeli Occupation Report by Who Profits Research Center January 2016 Who Profits from the Occupation is a research center dedicated to exposing the commercial involvement of Israeli and international companies in the continued Israeli control over Palestinian and Syrian land. Currently, we focus on three main areas of corporate involvement in the occupation: the settlement industry, economic exploitation and control over population. Who Profits operates an online database which includes information concerning companies that are commercially complicit in the occupation. Moreover, the center publishes in-depth reports and flash reports about industries, projects and specific companies. Who Profits also serves as an information center for queries regarding corporate involvement in the occupation – from individuals and civil society organizations working to end the Israeli occupation and to promote international law, corporate social responsibility, social justice and labor rights. www.whoprofits.org | [email protected] | P.O.B. 1084 | Tel-Aviv 6101001, Israel NOVACT-International Institute for Nonviolent Action promotes international peace-building actions in conflict situations. The Institute has been created through the collective effort of those active in international civil society to contribute to a peaceful, just and dignified world. Understanding nonviolence as
    [Show full text]
  • German Economic Policy and Forced Labor of Jews in the General Government, 1939–1943 Witold Wojciech Me¸Dykowski
    Macht Arbeit Frei? German Economic Policy and Forced Labor of Jews in the General Government, 1939–1943 Witold Wojciech Me¸dykowski Boston 2018 Jews of Poland Series Editor ANTONY POLONSKY (Brandeis University) Library of Congress Cataloging-in-Publication Data: the bibliographic record for this title is available from the Library of Congress. © Academic Studies Press, 2018 ISBN 978-1-61811-596-6 (hardcover) ISBN 978-1-61811-597-3 (electronic) Book design by Kryon Publishing Services (P) Ltd. www.kryonpublishing.com Academic Studies Press 28 Montfern Avenue Brighton, MA 02135, USA P: (617)782-6290 F: (857)241-3149 [email protected] www.academicstudiespress.com This publication is supported by An electronic version of this book is freely available, thanks to the support of libraries working with Knowledge Unlatched. KU is a collaborative initiative designed to make high quality books Open Access for the public good. The Open Access ISBN for this book is 978-1-61811-907-0. More information about the initiative and links to the Open Access version can be found at www.knowledgeunlatched.org. To Luba, with special thanks and gratitude Table of Contents Acknowledgements v Introduction vii Part One Chapter 1: The War against Poland and the Beginning of German Economic Policy in the Ocсupied Territory 1 Chapter 2: Forced Labor from the Period of Military Government until the Beginning of Ghettoization 18 Chapter 3: Forced Labor in the Ghettos and Labor Detachments 74 Chapter 4: Forced Labor in the Labor Camps 134 Part Two Chapter
    [Show full text]
  • Download The
    2019-2024 Global Homeland Security & Public Safety Market Volume 7 Homeland Security Research Corp. Global Homeland Security & Public Safety Market – 2019-2024. Volume 7 Global Homeland Security & Public Safety Market 2019-2024 Volume 7 Copyright © 2019 HSRC. All rights reserved | Copy #2019-010119-7 | 2 Global Homeland Security & Public Safety Market – 2019-2024. Volume 7 Table of Contents APPENDIX A (Continued) ................................................................................. 14 Middle East & Africa ......................................................................................... 14 1 Turkey Public Safety & Homeland Security Market ............................... 14 1.1 Turkey Public Safety & Homeland Security Market Background ...................................................................................... 14 Facts & Figures 2018 ............................................................ 14 Turkey Economy ................................................................... 14 Turkey Geopolitical Overview ................................................ 16 Turkey Homeland Security & Public Safety Market ............... 16 Crime in Turkey ..................................................................... 18 Terror in Turkey ..................................................................... 18 Turkey’s Counter Terror Legislation & Law Enforcement ...... 20 Turkey’s Homeland Security & Public Safety Agencies ......... 22 Turkey’s Police Forces .........................................................
    [Show full text]
  • DUBLIN Th Th May 5 – 8 2015
    ENFSI Drugs Working Group Conference DUBLIN th th May 5 – 8 2015 45 vítejte tere tulemast tervetuloa willkommen velkomin fáilte baroukh haba mobrdzandit benvenuto velkommen bienvenue laipni lūdzam üdvözlet merħba welkom bienvenidos dobrodošli witajcie bem-vindo vitame vás härzliche wöikomme dobrodošli hoş geldiniz välkommen 2 A Brief History of Dublin Castle Dublin Castle is situated in the very heart of historic Dublin. For more than 700 years, from 1200 until the formation of the Irish Republic in 1921, it was the centre of the English colonial administration in Ireland. A sprawling complex of historic buildings from between 930 and 1830, it offers a unique insight into Dublin‘s diverse history. In 930, the Vikings built fortifications at the junction of the River Liffey and its tributary, the now underground River Poddle. The site was called Dubh Linn in Irish, which means Black Pool. When the Normans invaded Dublin in 1169, they picked Dublin Castle as their stronghold. The first 'castle' in the proper sense of the word - stone walls and ditches - was completed by the English in 1230. The Great Courtyard of today corresponds closely with these fortifications, with the Record Tower as the last intact medieval tower of Dublin. The tower served as a high security prison in Tudor times. Dublin Castle was the dungeon for state prisoners and the seat of Parliament, which met in the Great Hall before the hall burnt down in the great fire of 1684 and Parliament moved to College Green in 1731. The Courts of Law and the Court of Exchequer also met at Dublin Castle.
    [Show full text]
  • Sources and Data Description
    OECD Regions and Cities at a Glance 2018 © OECD 2018 ANNEX B Sources and data description User guide: List of variables Variables used Page Chapter(s) Area 144 2 Business demography, births and deaths of enterprises 144 1 Employment at place of work and gross value added by industry 145 1 Foreign-born (migrants) 145 4 Gross domestic product (GDP) 146 1 Homicides 147 2 Household disposable income 148 2, 4 Households with broadband connection 149 2 Housing expenditures as a share of household disposable income 150 2 Income segregation in cities 151 4 Labour force, employment at place of residence by gender, unemployment 152 2 Labour force by educational attainment 152 2 Life expectancy at birth, total and by gender 153 2 Metropolitan population 154 4 Motor vehicle theft 155 2 Patents applications 155 1 PM2.5 particle concentration 155 2, 4 Population mobility among regions 156 3 Population, total, by age and gender 157 3 R&D expenditure and R&D personnel 158 1 Rooms per person (number of) 159 2 Subnational government expenditure, revenue, investment and debt 160 5 Voter turnout 160 2 Note on Israel: The statistical data for Israel are supplied by and under the responsibility of the relevant Israeli authorities. The use of such data by the OECD is without prejudice to the status of the Golan Heights, East Jerusalem and Israeli settlements in the West Bank under the terms of international law. 143 ANNEX B Area Country Source EU24 countries1 Eurostat: General and regional statistics, demographic statistics, population and area Australia Australian Bureau of Statistics (ABS), summing up SLAs Canada Statistics Canada http://www12.statcan.ca/english/census01/products/standard/popdwell/Table-CD-P.
    [Show full text]
  • Iacp New Members
    44 Canal Center Plaza, Suite 200 | Alexandria, VA 22314, USA | 703.836.6767 or 1.800.THEIACP | www.theIACP.org IACP NEW MEMBERS New member applications are published pursuant to the provisions of the IACP Constitution. If any active member in good standing objects to an applicant, written notice of the objection must be submitted to the Executive Director within 60 days of publication. The full membership listing can be found in the online member directory under the Participate tab of the IACP website. Associate members are indicated with an asterisk (*). All other listings are active members. Published November 1, 2019.
    [Show full text]
  • D1 Israel Police the National Headquarters Policing and Security
    D1 Israel Police The National Headquarters Policing and Security Division Bomb Laboratories Section National Headquarters Branch Telephone 02-5308987/8 Drafting date: Printing date: July 21, 2002 Case ZB/ 23 – 05650/01 Expert Opinion Reference: the Evidence Ordinance [New Version], 5731-1971. Name of the expert: Igor Peckerman His address: The National Headquarters / Bomb Disposal Department, Jerusalem. I, the undersigned, have been requested by: Zion police station to express my professional opinion on the following question: examination of exhibits in an investigation that was conducted by the police unit: Jerusalem Minorities, Case No: Detailed Incident 10283/01. I express this expert opinion instead of testifying in court and hereby declare that I am well aware, that for the purposes of penal law concerning perjury, this expert opinion, when signed by me, shall be considered as sworn evidence given in a court of law. The details of my education are: 1) Graduate of a bomb disposal course in the Israel Police in 1987. 2) Graduate of a course in electricity and electronics for Israel Police bomb disposal technicians in 1990. 3) Graduate of an explosion supervisor course of the Ministry of Labor in 1994. 4) Graduate of a senior bomb disposal technicians’ course in the Israel Police in 1996. 5) Graduate of a bomb laboratory operation team course in 1996. 6) Graduate of a specialized officers’ course in the Israel Police in 1998. 7) Graduate of an advanced explosion investigators’ course in the USA in 2000. My vocational experience: 1) Qualified bomb disposal technician in the Israel Police bomb disposal department since 1987.
    [Show full text]
  • Journal of Police & Society
    Journal: Journal of Police & Society: An Interdisciplinary Israeli Journal of Law Enforcement & Criminology Issue: No. 7 – Special Issue: Policing a Multicultural Society Date: April 2003 Source: Community & Civil Guard Department, Israel National Police Document No.: 242329 This document has not been published by the U.S. Department of Justice. To provide online access, NCJRS has made this material available in electronic format. Opinions or points of view expressed are those of the author(s) and do not necessarily reflect the official position or policies of the U.S. Department of Justice. At the turn of the century, multicultural communities are a growing phenomenon globally and in many cities throughout the United States. The world has witnessed increasing transnational migration of large groups of people due to a variety of factors worldwide. This movement has resulted in changes in the ethnic and cultural makeup of communities that are the destinations and sources of the migration. These changes present challenges for criminal justice practitioners and policymakers in the affected communities. For example, some cultures will allow only women to be questioned by a female police officer. A male may refuse to cooperate with a female police officer. Men from some cultures carry a ceremonial dagger next to their skin, which they would be reluctant to remove. Communication may be a problem, as not everyone speaks the same language. Poor language skills and a lack of cultural sensitivity may lead to unintended violence. Cooperation with law enforcement officers within ethnically homogeneous neighborhoods may not be forthcoming. Recruitment and retention of an ethnically diverse police force is both a challenge and a necessity.
    [Show full text]