Crime Scene Processing Series CRIME SCENE DIAGRAMMING New Mexico State Police

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Crime Scene Processing Series Crime Scene Processing Series CRIME SCENE CRIME SCENE DIAGRAMMING DIAGRAMMING New Mexico State Police New Mexico State Police Criminal Investigations Section Criminal Investigations Section Crime Scene Team Crime Scene Team

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Crime Scene Processing Series CRIME SCENE DIAGRAMMING New Mexico State Police Criminal Investigations Section Crime Scene Team. Learning Objectives. Understand the purpose for preparing a diagram Identify the information that must appear on a diagram - PowerPoint PPT Presentation

Transcript of Crime Scene Processing Series CRIME SCENE DIAGRAMMING New Mexico State Police

Page 1: Crime Scene Processing Series CRIME SCENE DIAGRAMMING New Mexico State Police

Crime Scene Processing SeriesCrime Scene Processing Series

CRIME SCENE CRIME SCENE DIAGRAMMINGDIAGRAMMING

New Mexico State PoliceNew Mexico State PoliceCriminal Investigations SectionCriminal Investigations Section

Crime Scene TeamCrime Scene Team

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Learning ObjectivesLearning Objectives

Understand the purpose for Understand the purpose for preparing a diagrampreparing a diagram

Identify the information that must Identify the information that must appear on a diagramappear on a diagram

Demonstrate knowledge and Demonstrate knowledge and proficiency in various methods of proficiency in various methods of incident scene diagramincident scene diagram

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Why do a Crime Scene Why do a Crime Scene Diagram?Diagram?

It establishes a permanent record of the It establishes a permanent record of the scenescene Associates evidence with the sceneAssociates evidence with the scene Supplements photographsSupplements photographs

Useful in orienting a person to the sceneUseful in orienting a person to the scene Witnesses can look at a diagram without Witnesses can look at a diagram without

being prejudiced…you can’t show witnesses being prejudiced…you can’t show witnesses photosphotos

Useful in CourtUseful in Court Easily blown-up for presentationEasily blown-up for presentation Not prejudicial to the juryNot prejudicial to the jury

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Why do a Diagram, cont.Why do a Diagram, cont.

The draw back of photos is that that The draw back of photos is that that they are a two- dimensional they are a two- dimensional representation of a three representation of a three dimensional objectdimensional object

Most photos distort the relationship Most photos distort the relationship of the photographed objects, causing of the photographed objects, causing items to appear closer or farther items to appear closer or farther apart than they actually areapart than they actually are

The sketch is a bird-eye view, which The sketch is a bird-eye view, which is hard to get with a camerais hard to get with a camera

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MethodsMethods

Grid (X/Y) CoordinatesGrid (X/Y) Coordinates Triangulation CoordinatesTriangulation Coordinates Polar CoordinatesPolar Coordinates Raw MeasurementsRaw Measurements

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Grid MethodGrid Method

The scene in divided into four The scene in divided into four quadrantsquadrants

Each item is measured at right-Each item is measured at right-angles from each axisangles from each axis

This is a great method because it is This is a great method because it is easy & efficienteasy & efficient

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Grid (X/Y) MethodGrid (X/Y) Method

X axis

Y a

xis

(origin)

The grid can also be expressed as north, south, east, and west measurements

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Grid (X/Y) MethodGrid (X/Y) Method

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Baseline MethodBaseline Method

Place a single line, dividing the Place a single line, dividing the scene in halfscene in half

Measure relative to the lineMeasure relative to the line Alone the baselineAlone the baseline At a right-angle to the baselineAt a right-angle to the baseline

Great for a diagram where you have Great for a diagram where you have no fixed reference pointsno fixed reference points

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Incident: Bone Scatter, Death InvestigationLocation: Chavez County, NMDate: 3/3/07

Drawn by: R. MathewsNot to Scale

N

Trees

Dry stream bed

skull

Leg bone

Leg bone

torso

Arm bone

Arm bone

REF. PT. 1N: 32 degrees 41.292’W: 105 degrees 13.951’

N

Ref. PT. 2N: 32 degrees 41.317’W: 105 degrees 14.003’

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Triangulation MethodTriangulation Method

Straight line distance measured Straight line distance measured from two (2) reference pointsfrom two (2) reference points

The item of evidence will be at the The item of evidence will be at the intersection of the intersection of intersection of the intersection of the two (2) arcsthe two (2) arcs

This is a very accurate method of This is a very accurate method of measuring measuring

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Triangulation MethodTriangulation Method

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Polar MethodPolar Method

Straight line distance measured from Straight line distance measured from a fixed reference pointa fixed reference point Measure the distance from the reference Measure the distance from the reference

point to the item of evidencepoint to the item of evidence Document the line’s azimuth from the Document the line’s azimuth from the

fixed reference point to the item of fixed reference point to the item of evidenceevidence

This is the best method for determining This is the best method for determining elevations above/below a fixed reference elevations above/below a fixed reference pointpoint

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Polar MethodPolar Method

12 ft @ 120 degrees 18 ft @ 100

degrees

North

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Raw MeasurementsRaw Measurements

The physical dimensions of a The physical dimensions of a room/arearoom/area

You should do this on every diagram You should do this on every diagram to complement the main method of to complement the main method of measurementmeasurement Width of roadsWidth of roads Distance from the victim’s hand to the Distance from the victim’s hand to the

gungun Overall dimensions of a roomOverall dimensions of a room

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Raw MeasurementsRaw Measurements

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Information added to a Information added to a USGS MapUSGS Map

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Sketching the Crime Sketching the Crime SceneScene

EquipmentEquipment Measuring tapes, rulersMeasuring tapes, rulers

Hammer, nails, shop clampsHammer, nails, shop clamps Laser range-finderLaser range-finder Graph paper and PENSILS (avoid using a Graph paper and PENSILS (avoid using a

pen)pen) GPSGPS Maps, blue-prints, aerial photosMaps, blue-prints, aerial photos Accident/crime scene templatesAccident/crime scene templates

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Sketching the Crime Sketching the Crime SceneScene

Its usually prepared in one of two waysIts usually prepared in one of two ways Bird’s-eye-view (straight down)Bird’s-eye-view (straight down) Elevation (cross section)Elevation (cross section)

Try to maintain proportionality (scale)Try to maintain proportionality (scale) Double-check your measurements to be Double-check your measurements to be

sure that they are correctsure that they are correct Especially important if calculations will later Especially important if calculations will later

be usedbe used Bloodstain pattern analysisBloodstain pattern analysis Accident reconstructionAccident reconstruction Shooting scene reconstructionShooting scene reconstruction

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Sketching the Crime Sketching the Crime SceneScene

Crime scene diagram is similar to Crime scene diagram is similar to diagramming an auto accident with injuriesdiagramming an auto accident with injuries

Use fixed reference points and reference Use fixed reference points and reference lineslines

Diagram the location of all evidence, Diagram the location of all evidence, including the bodyincluding the body Diagram the location of the head and the feet if Diagram the location of the head and the feet if

practical...otherwise, diagram the location of the practical...otherwise, diagram the location of the center-of-masscenter-of-mass

If you start a diagram & need to leave, make If you start a diagram & need to leave, make sure you pass on the responsibility to another sure you pass on the responsibility to another personperson

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Rough DraftRough Draft

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Finished productFinished product

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Sketching the Crime Sketching the Crime SceneScene

Use the rough-draft to make a finished Use the rough-draft to make a finished (court admissible) product(court admissible) product Hand-drawn is fine if you are a good artistHand-drawn is fine if you are a good artist

Use black ink and good paperUse black ink and good paper Use a templateUse a template

Computer generated sketches are preferableComputer generated sketches are preferable Can be easily reproduced without loss of qualityCan be easily reproduced without loss of quality Can be easily blown-up or added to Can be easily blown-up or added to Power PointPower Point

Maintain the original, rough sketchMaintain the original, rough sketch It is discoverable-just like your other field It is discoverable-just like your other field

notesnotes

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Things to put in the Things to put in the LegendLegend

Specific location of the sceneSpecific location of the scene Address, GPS Coordinate, etc.Address, GPS Coordinate, etc.

Date/Time Date/Time Case Number Case Number Preparer Preparer Scale (or scale disclaimer )Scale (or scale disclaimer ) Compass Orientation (North Arrow)Compass Orientation (North Arrow) Evidence NumbersEvidence Numbers Measurements Measurements

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Court room Court room presentationspresentations

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Court room presentationsCourt room presentations

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Court room Court room presentationspresentations

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Court room Court room presentationspresentations

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Court room Court room presentationspresentations

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Questions?Questions?