Analysing Crime-Scene Reports

Katerina Pastra and Horacio Saggion

University of Sheffield

Scene of Crime Information System

Outline

Project Overview SOCIS Architecture Corpus Linguistic Analysis Pointers

Project Overview

Domain: Scene of Crime Investigation (SOC)

Main Features :

1. Multimedia briefingSummarisation of text and images

2. GenerationOf formal reports & of photo albums

3. Intelligent Search

2000 - 2003

Project Overview (2)

Other systems for Crime Investigation:

Academic R&D Projects

Governmental agencies’ Systems

Commercial Systems

BUT: SOCIS brings ‘intelligence’ to CI systems

The ‘Digital Evidence in Court’ issue:

Authenticity has to be verified

Recently accepted in court

A view of SOCIS 143462

F

14 : 03 : 01

Offence: SUD Officer i/c: Pc Black

Location: 38 West Rd. Sheffield

Time Attended: 10:30 S.O.C.O Nick Helpful

Vehicle Reg. No: Stolen from: Found Abandoned:

Marks found (full description) FP Result

A

B

C

D

E

Number of Elimination Points Names and numbers of Police staff attending

Supplied CID/40As Left

M.O and Observations of examining officer - including instrument marks, tyre marks, footwearImpressions,, etc. together with details of Forensic samples/photographs taken

Attended the above location and examined scene of sudden death.

Body was clothed and lying on ground with large amount of blood around head on

Right side. A single base shotgun was lying on ground approximately 3’ from body.

2 spent cartridges were lying on ground either side of body.

Under body were 2 plastic bags with large number of cartridges. A small blood splatter

Was on wall behind body.

O720 called for supervision

0725 Photographed scene and body

NH/1 Single base shotgun with spent cartridge in breach

NH/2 Spent cartridge lying on ground to left of body

NH/3 Spent cartridge lying on ground to right of body

NH/4 8 live loose cartridges lying on ground under body

NH/4 10 line cartridges lying on ground under body in plastic bag

NH/5 Large number of live cartridges lying on ground under body in plastic bag

South Yorkshire Police

Scientific Support ServicesRef. No.

Date:

SP 746 MAR 00

CID/57

+

Image processing Text processing

Integrated Knowledge

Base

Text Processing

- Text Corpus

- Information Extraction system

>> Named Entities Recognition

>> Co-reference Resolution

Need:

Linguistic Analysis of the Language at the SOC

• Lexical Information

• Morphosyntactic Information

•Semantic Information

The Corpus

4 days spent with a SOCO:

12 scenes visited * 2 complete case files examined * official documentation collected

Official documentation :

SOC Reports = 77

Photo Indexes = 300

Witness Statements = 14

Reported SOC Information :

Press Association = 792

Washington Post = 233

Crime Watch = 8

NEEDED

Reports - Photo indexes Witness statements

Photographs

For the same case For major crime

Of significant quantity

Examples143462

F

14 : 03 : 01

Offence: SUD Officer i/c: Pc Black

Location: 38 West Rd. Sheffield

Time Attended: 10:30 S.O.C.O Nick Helpful

Vehicle Reg. No: Stolen from: Found Abandoned:

Marks found (full description) FP Result

A

B

C

D

E

Number of Elimination Points Names and numbers of Police staff attending

Supplied CID/40As Left

M.O and Observations of examining officer - including instrument marks, tyre marks, footwearImpressions,, etc. together with details of Forensic samples/photographs taken

Attended the above location and examined scene of sudden death.

Body was clothed and lying on ground with large amount of blood around head on

Right side. A single base shotgun was lying on ground approximately 3’ from body.

2 spent cartridges were lying on ground either side of body.

Under body were 2 plastic bags with large number of cartridges. A small blood splatter

Was on wall behind body.

O720 called for supervision

0725 Photographed scene and body

NH/1 Single base shotgun with spent cartridge in breach

NH/2 Spent cartridge lying on ground to left of body

NH/3 Spent cartridge lying on ground to right of body

NH/4 8 live loose cartridges lying on ground under body

NH/4 10 line cartridges lying on ground under body in plastic bag

NH/5 Large number of live cartridges lying on ground under body in plastic bag

South Yorkshire PoliceScientific Support Services

Ref. No.

Date:

SP 746 MAR 00

CID/57

Ref: 978675

Scenes of Crime Department

Photographic Index

Subject : Fatal R.T.A

Date : 30 - 12 - 97

Photographer : James Davis

1 - 4 Show Blackburn Road Rotherham looking in the general direction of Tusley

5 Shows Blackburn Road looking in the opposite direction (towards Ecclesfield)

6 Shows Vauxhall Cavalier C666HET together with pedal cycle in Blackburn Road

7 Shows damage to Vauxhall Cavalier

8 Shows damage to pedal cycle

9 View of foot - bridge

SOC Language Characteristics

General Characteristics:

Telegraphic

Descriptive

Accurate

Objective

Special text type : Reports

Lexical Information

Characteristics:

- Extensive use of abbreviations

- Jargon

Creation of Word - Lists (gazetteers):

- Based on PITO’s CDM

- Over 200 lists (domain + general)

Words of interest are assigned a semantic category

Morphosyntactic Features Extensive Ellipsis

Simple temporal dimensions

Limited co-ordination

Sub-ordination avoided

POS : NPs, PPs

Adjuncts of place - time, Qualifiers

For identifying entities of interest automatically, we need to write specific rules using:

The word lists + Context Information

Modelling (1) OFFENCES

MURDER

VIOLENT ASSAULT

ROBBERY …..

TIME ORGANISATIONS ACTIVITIES

DATE

commercial official…governmental criminaljudicialeducational…

PERSONS EVIDENCE

SOCPERSONS

NAMES ROLESUSPECT

OCCUPATION BODY PARTS OFFENDER

VICTIM…PHYSICAL

CHARACTERISTICS

colour (eye colour, skin colour, hair colour…)agesexnationality

SCENE OF CRIME

date people involved time location evidence

Modelling (2) EVIDENCE

CONDITION OF EVIDENCE

FUNCTIONAL EVIDENCE

CONDITION OF THE BODY

POSITION OF THE EVIDENCE

POSITIONAL EVIDENCE

POSITION OF THE BODY

REAL EVIDENCE

CHATTELS (any moveable property: clothing…) DOCUMENTS (check, notebook, letter…) PHOTOGRAPHS - FILMS - RECORDINGS

INSTRUMENTS SOCO INSTRUMENTS

CRIMINAL INSTRUMENTS

TRACE EVIDENCE

DIRECT IDENTIFICATION INDIRECT IDENTIFICATION

Body fluids Transfer evidence (glass, fibres, paint) Teeth Fire accelerants Fingerprints Gunshot residues Tracks ……. Impression Evidence

Marks

Pointers

SOCIS Sheffield Web Page

http://www.dcs.shef.ac.uk/nlp/socis

SOCIS Surrey Web Page

http://www.computing.surrey.ac.uk/ai/socis

NLP Group

http://www.dcs.shef.ac.uk/nlp