Crime Scene Investigation Laboratory Manual - Exercise J - Crime Scene Documentation: Sketching

Oct 29, 2026

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Practice techniques for accurate crime scene documentation through measurement-focused sketching. The manual explains how crime scene sketches provide the permanent record of size and distance relationships between the scene and physical evidence, and how sketches must correlate with still photographs to support evidence relevance, reliability, and validity. It covers rough versus to-scale finished sketches, overhead and side perspectives, and planning and organization skills. It also teaches three measurement methods—triangulation, polar coordinates, and base line/fixed line—plus documentation elements required in the sketch, including agency case number, incident type, location, timing, personnel, scale, and legend.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages13

Reading Time33 min

AccessFree to download

Objective

Crime Scene Sketching Purpose and Documentation Value

Rough vs. Final (To-Scale) Sketches

Overhead (Bird’s-Eye) vs. Elevation (Side View) Perspectives

Planning and Organizational Requirements

Measurement Techniques for Sketching

Triangulation

Polar Coordinates

Base Line or Fixed Line

Required Sketch Information and Legend

Case Number, Incident Type, Victim Names, Location, Timing, Personnel, Scale

Physical Evidence Legend

Crime Scene lnvestigationLaboratory Manual Marilyn T.Miller.Ed.D. CRIME SCENEINVESTIGATIONLABORATORYMANUAL MARILYN T.MILLER,ED.D. CRIME SCENE INVESTIGATION LABORATORYMANUAL Actioities for the student to use triangulation,base line,and other measurement techniques arepresented,as well as examples of the use of 3-D laser scanners at crime scenes as critical thinkingexercises. # Objective To practice techniques of measurement as a component of crime scene documentation and applythem to mock crime scenes The final component of crime scene documentation is the preparation of the crime scenesketch or diagram.Sketching at the crime scene is not about drawing;it is about measur-ing.Still photography is a two-dimensional representation of three-dimensional areas anditems.It will,therefore,inherently result in some distortion of the spatial relationship ofobjects in the photographs.Common examples of the distortions are found in the recon-struction of shooting trajectories or bloodshed points of origin. The crime scene sketch is the permanent record of the actual size and distance relation-ships between the crime scene and its physical evidence.The sketch must correlate andsupplement the still photographs taken at the scene.The sketch further supports the rel-evancy,reliability,and validity of physical evidence found at the crime scene. Crime scene sketch preparation requires some planning and organizational skills by thecrime scene investigator.There are two basic types of crime scene sketches that are partof a crime scene investigation:a rough sketch and a to-scale,finished,or final sketch (seeFigure J.1).There are two basic types of perspectives that are used for crime scene sketches:the overhead or "bird's-eye view"and the elevation or“side view"(see Figure J.2). A rough sketch is made at the crime scene before evidence collection.It shows all the evi-dence to be collected,major structures present in the crime scene,and other relevant struc-tures in or near the crime scene.The rough sketch will show all the measurements taken todetermine the size and distance relationships at the crime scene.Afinal or finished sketch,drawn to scale,is prepared from the rough sketch.The final sketch is normally preparedfor courtroom presentation.It will show the relevant structures within the crime sceneand all items of evidence.It should never show any measurements.It has a clean,unclut-tered appearance. A crime scene sketch is usually drawn from a looking-down or overhead perspective.Thistype of perspective is the most common type and is most recognizable by other investiga-tors and juries.The side-view sketch can be used for supplementing the still photographydocumentation.The crime scene sketcher should be prepared to combine sketch types and 网 EXERCISEJ CRIME SCENE DOCUMENTATION:SKETCHING Rough Sketch:(Courtesy of Ashley Dumbrill) Final Sketch: FINAL SKETCH:Room on Top Floor1020 Main Street,Richmond,VALEGENDFIGURE J.1 Rough and final sketches. 【颗图 Overhead Sketch: Projected View Sketch FIGURE J.2 Overhead sketch and projected view sketch. EXERCISEJ CRIME SCENE DOCUMENTATION:SKETCHING add photographs to supplement the documentation.Digital drawing programs along withdigital images make this an easily accomplished task.Three-dimensional sketching is notnormally done,but measurements can be used in a number of computer-aided drawingprograms and can occasionally be used for 3-D model construction (see Figure J.3). There are three measuring techniques for sketching the crime scene and evidence:triangulation,polar coordinates,and base line or fixed line.All three measurement techniques (seeFigure J.4)are based upon the determination of fixed,or known,starting points.The fixedpoints should be permanent;however,the name "fixed"indicates a known location,notnecessarily permanency. 1.Triangulation—Select two fixed points,measure the distance between them,andprepare a basic layout sketch of the scene wit

FAQs

Why is crime scene sketching considered measurement rather than drawing?

Crime scene sketching depends on accurate measurement to represent the size and distance relationships between the scene and evidence. Unlike photographs that can introduce spatial distortion, sketches serve as the permanent record that correlates with still images.

What is the difference between a rough sketch and a finished (final) sketch?

A rough sketch is created at the scene before evidence collection and shows evidence, structures, and all measurements taken. A final sketch is drawn to scale from the rough sketch for courtroom presentation and should not show any measurements.

What three measuring techniques are taught for sketching evidence?

The manual presents triangulation, polar coordinates, and base line (fixed line) techniques. All rely on determining fixed or known starting points, then measuring evidence from those references using distances and angles or perpendiculars.

Oct 29, 2026

Upload by Aldword