the geek and the gumshoe or can mathematics and computers really solve crimes?

8/8/2019 The Geek and the Gumshoe or Can Mathematics and Computers Really Solve Crimes?

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³The Geek and the Gumshoe´or

³Can Mathematics and

Computers Really SolveCrimes?´

Michael ³theprez98´ Schearer Frank ³Thorn´ Thornton



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Introduction



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Who are we, and why are wehere?



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The Geek: Michael Schearer Fascinated by the application of

mathematics to real-world situations

Recently separated from nearly 9 years inthe U.S. Navy (flying aircraft) Currently working for a U.S. government

contractor in Maryland (flying a desk)

Contributing author to PenetrationTester's Open Source Toolkit (Volume 2)Netcat Power Tools (April 2008), andmaybe more!

Football coach and proud father of three



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When did

Frank start as a cop?



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Looking forward«



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The Gumshoe:F

rank Thornton Law Enforcement Officer, 1980 ± 2002. Served

in a variety of ranks and positions from PatrolOfficer to Chief of Police. Also worked in VT

Forensic Lab on Latent Fingerprints and crimescene investigations. Rated as a Class I (Homicide) Death Investigator by Vermont¶sOffice of the Chief Medical Examiner

Hacking computers since ~1973 Helped create ANSI Standard ³ANSI/NIST-CSL

1-1993 Data Format for the Interchange of Fingerprint Information´

Author and co-author of a half-dozen books oncomputer security. (Cheerfully blatant plug!)



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Agenda Introduction

± Explanation

± Videos ± Perceptions

Math, Computers & Crime ±Math in everyday life ±Math and crime-fighting

Conclusions

Questions & Answers



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Police Investigations Are ALL About Collecting Data

Who

What

When

WhereHow



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Investigations differ from other data collection in several areas

Everyone lies to the police. Fact has to be separated from:

-Lies.-Fiction.-Opinion.-Other false positives. (May be thousands)

Eye witnesses have a high credibility withprosecutors and juries, less so with cops.

Everyone lies to the police. Failure can be dangerous to the public. Did we mention that everyone lies to the police?



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Information = Data

This is sometimes recognized at some level.Joseph Wambaugh, ex-LAPD Detective,

award winning mystery novelist andscreenwriter wrote this in The Black Marble:

³ Clarence looked around at the roar of

activity, at the grinding paper mill. Paper everywhere. Take away my gun and car,but pl ease don't take my pencils.´



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Information = Data

³ You walked in withinformation and a

pretty face.

You can¶t leave

with both.´



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Doesn¶t it really work like on CSI?

The CSI Effect

Perception and Reality

± DNA Testing ± AFIS Searches ± School-Associated Violence ± Cops are always doing exciting things like

getting in fights or shooting bad guys



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So, knowing all that, what other tools are available to help

investigations?



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So let¶s explore how math andcomputer technology can helpwith investigations«

³Time for sc i ence!´



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Math is everywhere. Elections

± Voting, exit polls, voter identification/analysis

Sports ± Statistics, sabermetrics, betting/sports book

Lottery ± Probability (or perhaps improbability!)

Math in advertising ± frequency atlas, Google advertisements, British

two pound coin



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B

illboard say what?



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What is wrong with this picture?



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Can Mathematics andComputers Really Solve

Crimes?



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Crash Reconstruction Collision evidence

± positions of rest, skid marks, roadway markings,damage to vehicles, damage to property

Other evidence ± Witness recollections, traffic control devices,

weather conditions, lighting issues

Available specifications

± Newton¶s laws of motion Collision reconstruction techniques

± Damaged-based ± trajectory-based



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Image Deblurring

³Enhance«enhance«enhance«´

Blurring is typically caused by movement

during the capture process by the camera or by the subject, or an out of focus lens

Deblurring involves finding a mathematicaldescription of how the image was blurred



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Image Deblurring

Before« After



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Image Deblurring

A camera captured this image

Image deblurring produced this image



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Deblurring Fingerprints

A very touchy subject! By deblurring afingerprint, are non-existent details being

added to a latent print? Typically, any enhancement (fingerprint or

otherwise) must be verifiable and able to beduplicated by another expert

The risk in ³crossing the line´ is highlydependent upon use of tools



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Fingerprint Matching

Different vendors use different algorithms

10 different Fingerprint Individuality models

Minutiae matching vs. Pattern matching Speed and throughput vs. accuracy

Error rates

± TypeI(FP, FRR) vs. Type

II(FN, FAR) ± Crossover or Equal Error Rate

± Security vs. Forensic Science



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Receiver Operating Characteristics



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Fingerprint Classification



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Escape Math Variables

± Time, Method of travel, Achievable speeds,Traffic density, Traffic choke points

Dijkstra¶s algorithm ± Link-state routing protocols (OSPF), MapQuest,

Google Maps

Random walks ± Calculate distance escaped POWs could travel

in WW2

Trawler problem Drive-time calculations (MapPoint) Social network analysis (to be discussed

later)



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Dijkstra¶sAlgorithm



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Random walks



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Trawler problem



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Narrowing the Suspect Pool

Profiling ± Psychological/criminal

± Geographic (to be discussed later) Venn diagrams



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Social Networks Social network analysis

± Google¶s PageRank algorithm is an example of network analysis

± Organized crime, gangs, terrorist cells,

individuals, other organizations ± Social relationships in terms of nodes and ties ± Determine the social capital of individual actors

Things to consider

± Who are someone¶s closest friends/associates? ± Where might that person flee to? ± Structural cohesion: could you eliminate a

specific individual from a group which couldcause that group to collapse?



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Socialnetwork of aproject team



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Social network of 9 /11 terrorists



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Crime Mapping

Choropleths

Pin Mapping

Hot Spot Analysis Geographic Profiling



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France,1829

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London,September 1854

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Choropleths and Pin Mapping

NYPD has used traditional pin mapping sinceat least 1900

University of Chicago researchers mappedcrime in Chicago neighborhoods (1920-30s)

These methods of mapping helped to identifyrelationships between crime and

neighborhoods, social disorganization,poverty, and physical deterioration

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Automated Crime Mapping

Automated mapping began in the late 1960s ± Did not really ³take off´ until the 1990s

Hot Spot Analysis ± Finding geographic concentrations of types of crimes; finding causes for those hot spots;aggressive policing in those areas

Geographic profiling ± If psychological profiling tells you ³who´,geographic profiling tells you ³where´

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Hot Spot Analysis

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Hot Spot Analysis

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Geographic Profiling

If Psychological/criminal profiling tells you³who´, geographic profiling tell you ³where´

Suitable for serial crimes: murder, rape,robbery, arson, predatory crimes

Gives police a starting point from which tonarrow down lists of suspects

Does not replace traditional investigativetechniques, but supplements them to helpmanage the large volume of information

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Geographic Profiling

CrimeStat, Dragnet, Predator, Rigel

Theory is based upon ³journey to crime´ and

³principle of least effort´ ³Journey to crime´ varies among type of

crime, age, race, etc.

Includes a buffer zone around the offender¶shome or base of operations

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Saanich Serial Arsonist

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Jeopardy Surface

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Probability of Offender

Residence

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GeoProfile

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Some Other Examples

Spherical Trigonometry: Determiningposition on Earth based on two like

photographs (with a few caveats«) Prisoner¶s dilemma: Is it better to cooperate

or defect?

Steganography and covert channels:

Finding hidden information Predictive Analysis: Predicting the location

of a serial event

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The Future is Now: RTTC

26-member staff, on 24/7/365 15 workstations, divided among teams of

officers Each team has a particular assignment, suchas homicides or shootings

Satellite imaging

Precinct-by-precinct maps Ties together information to solve crimes 2-story tall projection screens

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NYPD Real Time Crime Center

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The Future is Now: RTTC

Cognos data warehouse, using IBM OmniFind 8.2on SUSE Linux blade servers

Link Analysis Capacity can call up all knownaddresses for a suspect and known associates

When a crime occurs, any number of searches of public records are then run: ± Over 5 million NYS criminal records, parole and

probation files ± Over 20 million New York City criminal complaints,911/311 calls and summonses spanning five years

± Over 31 million national crime records ± Over 33 billion public records.

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Conclusions

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References

Mark Bridger, Northeastern University Valdis Krebs @ orgnet.com David Weisburd and Tom McEwen, ³CrimeMapping and Crime Prevention´

Dr. Kim Rossmo, Texas State University Rob Gebeloff, NJ Star-Ledger Dr. Raymond Chan, CUHK

Mitsubishi Electronic Research Laboratories Zeno Geradts, Netherlands Forensic Institute Henry C. Lee and R.E. Gaensslen, Advances in

Fingerprint Technology, 2nd Ed.

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Questions & Answers

the geek and the gumshoe or can mathematics and computers really solve crimes?

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