MAPPING AND ANALYTICAL APPLICATIONS OF GIS IN CRIME AND SECURITY ANALYSIS by Dr. Yuri Gorokhovich,...

MAPPING AND ANALYTICAL APPLICATIONS OF GIS IN CRIME AND SECURITY ANALYSIS

by

Dr. Yuri Gorokhovich, Assistant Professor, SUNY Purchase College

Dr. Victor Goldsmith, Associate Provost for Research and Economic Development, Pace University

First NSF/NIJ Symposium on Intelligence and

Security Informatics (ISI 2003)

Tucson, AZ

June 2-3, 2003

Context of Research – Project Safe Neighborhood

Project Safe Neighborhoods (PSN) is a nationwide commitment to reduce gun crime in America by networking existing local programs that target gun crime and providing those programs with additional tools necessary to be successful. The Bush Administration will seek to commit $533 million to this effort over two years, including $233.6 million already available for this year. This funding will be used to hire new federal and state prosecutors, support investigators, provide training, and develop and promote community outreach efforts.

The Purpose of the Talk:

1. Discuss various GIS mapping and analytical techniques.

2. Show their application to ATF data.

3. Demonstrate complex relationship between data variables

4. Demonstrate importance of combination of various GIS techniques to create better “hot spots”.

PSN Program Goals

The goals of this program are:

(1) to increase the capacity of PSN Task Forces to design data driven strategies that produce measurable decreases in firearm-related violent crime;

(2) to improve the long term ability of federal, state, and local partners to work together to understand, prosecute, and prevent firearm related violent crime within their jurisdictions.

NEW YORK STATE JUDICIAL DISTRICTS OF THE STUDY

EASTERN DISTRICT:

Suffolk Nassau Queens Brooklyn

SOUTHERN DISTRICT:

Westchester Bronx Manhattan Staten Island

ATF Gun Recoveries 1999 - 2003

District County Number of Gun Recoveries

Southern

Bronx 6696

Manhattan 743

Staten Island 979

Westchester 187

Eastern

Brooklyn 11330

Queens 2631

Nassau 913

Suffolk 901

Variety of Gun Dealer’s Premises per District and County

(top five):

District County Dealer’s Premise State

Number of recoveries

Southern Bronx FL

OH

CA

VA

NY

1305

1037

1010

949

881

Manhattan OH

CA

FL

CT

SC

173

161

158

118

115

Staten Island NY

FL

OH

CA

CT

231

213

171

151

132

Westchester NY

FL

VA

OH

SC

50

32

22

22

20

Variety of Gun Dealer’s Premises per District and County

(top five):

District County Dealer’s Premise State

Number of recoveries

Eastern Brooklyn FL

CA

OH

NY

MA

2076

1726

1664

1479

1274

Queens NY

FL

CA

CT

OH

501

468

348

315

308

Suffolk NY

FL

CT

CA

MA

258

169

169

137

136

Nassau FL

NY

CA

MA

OH

186

154

137

128

120

District County Gun Type Number of recoveries

Southern Bronx P

PR

S

R

PD

Z

M

DD

4088

1670

433

401

88

8

5

3

Manhattan P

PR

R

S

PD

494

173

33

31

12

Staten Island P

PR

R

S

PD

Z

483

230

177

81

7

1

Westchester P

PR

S

R

PD

M

84

56

21

17

8

1

Variety of Gun Types per District and County:

Codes:

P - pistol

PR - revolver

S - shotgun

R - rifle

PD - derringer

Z - unknown

M - machine gun

DD - destructive device

Variety of Gun Types per District and County:

District County Gun Type Number of recoveries

Eastern Brooklyn P

PR

R

S

PD

Z

M

C

DD

6521

3123

807

706

139

16

12

5

1

Queens P

PR

R

S

PD

Z

M

1414

612

301

257

41

4

2

Suffolk P

PR

R

S

PD

Z

M

C

400

210

166

104

17

2

1

1

Nassau P

PR

R

S

PD

Z

479

277

83

61

12

1

Codes:

P - pistol

PR - revolver

S - shotgun

R - rifle

PD - derringer

Z - unknown

M - machine gun

DD - destructive device

District County Recovery location

Number of recoveries

Southern Bronx Unknown

1

24

17

19

6194

322

99

46

7

Manhattan Unknown

1

24

17

12

622

43

29

23

8

Staten Island Unknown

1

24

17

16

908

28

27

4

3

Westchester Unknown

1

22

16

13

181

3

1

1

1

Variety of Gun Recovery Locations (top five) per District and County:

Code:

1 – intersection

7 – police station

12 - vehicle

13 – airport

16 - bar

17 – apartment

19 – store

22 – vacant lot

23 – business

24 - residence

District County Recovery Location

Number of recoveries

Eastern Brooklyn Unknown

1

24

17

19

10444

605

123

82

22

Queens Unknown

1

17

24

13

2352

142

46

45

21

Suffolk Unknown

24

23

22

19

824

60

7

3

2

Nassau Unknown

24

7

1

17

808

34

29

21

7

Variety of Gun Recovery Locations (top five) per District and County:

Code:

1 – intersection

7 – police station

12 - vehicle

13 – airport

16 - bar

17 – apartment

19 – store

22 – vacant lot

23 – business

24 - residence

Complexities of ATFE Database:

1. Gun dealers come from various states outside NY districts and some gun dealerships supply guns from NY

2. Most of recovery locations are not known. From available data the majority of recovery locations are associated with: intersections; residences; apartments; bars; stores; vacant lots; airports

3. There is apparent relationship with locations of existing crime patterns (hot spots), schools and other public facilities and land uses.

SPATIAL UNITS IN CRIME ANALYSIS

There are three kind of spatial units stored in ATFE database that can be used for crime mapping:

1. Geographic coordinates (point), derived from street address;

2. Zip code (polygon);

3. Administrative unit i.e. borough, town, state (polygon);

All spatial units correspond to one of the following topological sequence:

Point – Line – Polygon

In this sequence, a point represents lowest level of topology and serves as an elementary building block for all other topological types (i.e. lines and polygons)

SPATIAL UNITS IN CRIME ANALYSIS

ACCURACY:

The most accurate unit is geographic coordinate pair. It allows “pinpoint” crime spot and can be used in variety of mapping techniques, including density mapping and proximity analysis among others.

Zip code and administrative boundaries are relatively large areas and have high spatial uncertainty within their boundaries.

CONTEXT:

Administrative boundaries (including boroughs, villages, townships) have their own regulations on traffic, parking, general security and “land uses”. These factors can affect crime and gun possession. From this point of view these administrative boundaries can be used as spatial units for analysis. While spatial techniques such as density mapping or proximity analysis are difficult to implement with these units, they would be suitable for the multivariate or descriptive statistics.

SPATIAL UNITS IN CRIME ANALYSIS

CONCLUSION:

Geographic locations (i.e. points) of recovery data are more useful for the analysis of crime because they represent lowest level of topology in spatial data, provide basis for other topologic types and can be analyzed with any GIS technique.

Address Matching and Geocoding Technique Using Census TIGER Street Data

Fulton St

Address Matching and Geocoding (Interpolation Using TIGER Data)

Fulton StX1, Y1

X2, Y2

Length

From address right

= 135

To address right

= 167150 Fulton St

Coordinate Pair: Longitude Latitude

CRIME MAPPING TECHNIQUES: THEMATIC MAPS

NOT REPRESENTATIVE, HIGH SPATIAL UNCERTAINTY

Recovery of guns in Staten Island and Brooklyn, 1999 - 2003

Data Source: ATFE, West Virginia

Red dots are for 23,315 recoveries for the time period

CRIME MAPPING: USING POINT DATA ATTRIBUTES

Recovery of guns in Staten Island and Brooklyn, 1999 - 2003

Data Source: ATFE, West Virginia

Red dots indicate locations with > 5 recoveries

CRIME MAPPING: USING POINT DATA ATTRIBUTES

Recovery of guns in Staten Island and Brooklyn, 1999 - 2003

Data Source: ATFE, West Virginia

Red dots indicate locations with > 20 recoveries

CRIME MAPPING: USING POINT DATA ATTRIBUTES

Recovery of guns in Staten Island and Brooklyn, 1999 - 2003

Data Source: ATFE, West Virginia

Red dots indicate locations with > 50 recoveries

CRIME MAPPING: USING POINT DATA ATTRIBUTES

Recovery of guns in Bronx, 1999 - 2003

Typical Point Data Map

CRIME MAPPING TECHNIQUES : Unique Symbol

# 1 - 3# 4 - 5# 6 - 8

Legend:

Number of dealers per

recovery location:

CRIME MAPPING TECHNIQUES : Graduated Symbol & Color Codes

Gun Recoveries: Number of gun dealers associated with the recovery location

Data Source: ATFE, West Virginia

Legend:

Number of gun types per

recovery location:

CRIME MAPPING TECHNIQUES : Graduated Symbol & Color Codes

Gun Recoveries: Number of gun types associated with the recovery location

Data Source: ATFE, West Virginia

# 1 - 2 # 3 - 4# 5 - 6

CRIME MAPPING TECHNIQUES : Proximity of Recovery Locations

Red segments represent < 0.5 miles proximity between recovery locations

Data Source: ATFE, West Virginia

Gun “neighborhoods”

Bronx

CRIME MAPPING TECHNIQUES : Contour Line Densities

Denser Pattern of Contour Lines Corresponds to the Higher Level of Recoveries

Data Source: ATFE, West Virginia

Advantage of Contour Line Densities:They show orientation of the recovery“field” i.e. changes as a result of police intervention strategies.

Recovery of guns in Staten Island and Brooklyn, 1999 - 2003

Data Source: ATFE, West Virginia

Number of recoveries per sq. mile

CRIME MAPPING TECHNIQUES :

“HOT SPOTS” – TRADITIONAL DENSITY ANALYSIS

Density:0 - 2 0 02 0 0 - 4 0 04 0 0 - 6 0 06 0 0 - 8 0 08 0 0 - 1 0 0 01 0 0 0 - 1 2 0 01 2 0 0 - 1 4 0 0> 1 4 0 0

CRIME MAPPING TECHNIQUES : 3D Visualization

Data Source: ATFE, West Virginia

Points are recovery locations.

Intensity of color shows rate of recovery.

CRIME ANALYSIS: USE OF DEMOGRAPHIC SPATIAL DATA

Census Tracts

Census tracts allow the extraction of demographic data and to overlay demographics with crime data. The resultant mapping and analysis will lack spatial pattern and precision as previously shown.

Census Blocks

CRIME ANALYSIS: USE OF DEMOGRAPHIC SPATIAL DATA

Census Blocks allow to extract demographic data and overlay them with crime data. Their spatial pattern and precision are finer than census tracts.

1. Density mapping, proximity and demographic analysis are most important categories of scientific tools for research on crime. Geographic coordinates provide basis for these analyses. Therefore their collection is very important. However, for locating crime and report preparation street addresses are traditionally used by police and other municipal agencies. GIS geocoding technique links street addresses and geographic locations if street data contain correct street address and zip code/city/borough.

2. Available GIS analytical and mapping techniques allow to create new kind of “hot spots”, based on combination of multiple factors from ATFE database, such as: frequency of gun recoveries, frequency of recovery dates and proximity between recovery locations. Traditional “hot spot” technique is based primarily on recovery frequencies and uses an arbitrary “radius” for the kernel smoothing technique.

3. Design of GPS coupled with GIS-based street map would allow automatic collection of crime data in the field in both formats: street address and geographic location. This would save time for police officer preparing report, reduce cost of initial data preparation for analysis and allow use of data in real-time response measure if needed.

CONCLUSIONS: