interFIRE Home interFIRE Home interFIRE VR Support Training Calendar Training Center Resource Center Message Board Insurance Info

Demonstrative Aids: A Case Study Using interFIRE VRs

By Cathleen Corbitt-Dipierro
Interactive Designer, interFIRE VR

Demonstrative aids, usually presented during the court testimony of an expert witness, can greatly assist the jury in understanding the case and the facts as presented and interpreted by the expert. If a demonstrative aid is an actual piece of evidence ("demonstrative evidence"), NFPA 921 recommends that it be authenticated through either witness identification or chain of custody.

To help investigators understand and visualize the strong demonstrative aids they can create, this article reviews the most common types of demonstrative aids and presents sample fictional exhibits based on the facts of the interFIRE VR case at 5 Canal Street.

Scene Diagrams

The most basic scene diagram is the floor plan. At minimum, this scale diagram shows the rooms in the structure, significant furnishings and features of the structure, and location of victims. Notation of important investigative features. Many other different types of diagrams are possible: elevation sketches, pre-fire contents drawings, exploded room diagram showing investigative information such as patterns and charring, evidence sampling location sketches, canine alert location sketches, photo location diagrams, and witness perspective locations. Each case dictates what sketches are appropriate beyond the basic "floor plan." All diagrams should be labeled with the name of the case, the name and address of the structure, a key of symbols, a notation of North directional, and the name of the investigator or schematic artist who created the diagram. Below, on the left, is a basic diagram of the floor plan of the house at 5 Canal Street in interFIRE VR. On the right is an example of a second, specialty diagram, with dimensions overlayed.

For interFIRE VR, Robert Corry1, Principal Investigator for Forensic Investigation & Technical Services LLC and former Assistant Vice President and Fire Investigation Specialist at American Re-Insurance Company, suggests, "Your grounds diagram could be on a scale that would permit the witness who found the tire track on the edge of the road to mark the location so jurors could see its relationship to the house. The same could be done by the investigator for the location of the water bottle in the woods." In preparing sketches for courtroom presentation, consider how they will be used, by what witnesses, and what scale and features should be chosen so the diagram can be effectively used by them.

Photographs and Annotated Photographs

Photos depicting critical information or evidence can be blown up to poster-size and used during testimony. Examples of situations to depict with large photographs include:

  • unusually shaped burn patterns
  • remains of trailers
  • evidence items
  • heat and burning indicators like distorted lightbulbs
  • damage patterns on victims

Sequential photos and photo mosaics can also demonstrate important scene features.

In the interFIRE VR case, a photograph showing the locations of canine alerts can assist the jury in understanding the pour pattern. On the right is an example of how this demonstrative aid might be prepared.

Aerial photographs can assist the jury in understanding the structure, its relationship to other buildings, and accurately placing important locations in a geographic context. Joseph Toscano2, Fire Investigation & Litigation Support Consultant for Chilworth Technology and former Vice President Fire Investigation Specialist for American Re-Insurance Company, and frequent instructor on demonstrative aids, recommends, "Take several aerial photographs, and depending on the circumstances, use as many as possible. In a city environment I recommend that one of the photos include the victim property and the location of the nearest firehouse. This photo is utilized by the firefighter witnesses who will begin the process of bringing the jury back to the fire scene. Certainly one for utilization by any eyewitnesses, path of flight, location of evidence away from fire scene, and the like."

In the interFIRE VR case, the expert witness might use an aerial photograph comprising the property, the woods behind it, and the road beyond those woods to illustrate the proximity of the house to the woods, the location of the water bottle in the woods, the location where the tire print was found, and the location where Meghan Branigan saw the car parked on the road. Ms. Branigan can also point out this location on the same photograph. A wider aerial photograph could be plotted with Meghan Branigan's paper route and Daniel Mezzi's jogging route to help the jury understand the movements they detail and how their observations figured into the investigator's analysis. Aerial photographs can also be used at sites where the roofing is burned away, exposing the building interior, and providing an overhead view of where evidence items were found, patterns exposed, or features noted.


Timelines help a jury understand the sequence of events surrounding a fire. The more complex the movements, the more critical a timeline is to helping jurors keep the facts straight. The timeline also helps illustrate inconsistencies in a suspect's statements, gaps of time unaccounted for by a suspect's statements, and the physical time limits of movements (i.e., how long it takes to get from one place to the next). Depending on the case, multiple timelines may be necessary.

The following example is a sample timeline for the major events in the 5 Canal Street case from interFIRE VR (NOTE: This sample timeline does not necessarily reflect the actual events and responsible parties in interFIRE VR):

Key Physical Evidence

Above: Example of Demonstrative Evidence from interFIRE VR

Above: Example of Physical Indicators from interFIRE VR

Above: Example 1 of Document Evidence from interFIRE VR

Above: Example 2 of Document Evidence from interFIRE VR

Toscano notes "Perhaps the most dynamic piece of demonstrative evidence that I recommend investigators consider is a section of floor that has a burn pattern the investigator is utilizing in part to form an opinion. Aside from the traditional methods of documenting the scene—photos, diagrams, video—the best evidence is always the evidence itself." Corry succinctly concurs, "If a piece of furniture or section of flooring has a burn pattern of interest—cut it out, mount it and bring it to court." Allowing the jury to see the burn pattern as the investigator describes how it could have been caused is invaluable. This piece of demonstrative evidence can also be used by forensic examiners who will offer testimony regarding the results of samples collected from the pattern.

Key physical evidence can also include potential accidental causes that were eliminated. These can be especially important if a suspect attempted to make the fire look like an accidental fire caused by mechanical or electrical malfunction, and the investigator anticipates that this possible cause will be raised by the defense at trial. For example, in the interFIRE VR case, the investigator could collect the space heater (represented here in photographs, but would be presented in court in real life) and the electrical outlet behind the couch. At trial, while discussing how these causes were eliminated, the investigator could actually show the jury the factors he/she used to make their determination: for example, the absence of spark marks on the back of the outlet. It is very powerful for the jury to see this with their own eyes on the actual piece of equipment.

Physical Evidence of Indicators

Collecting key indicators of fire origin and/or spread can provide the jury with a firsthand look at what the investigator saw and allow them to explain their interpretations of the evidence. As an example of the use of physical evidence of indicators at trial, Toscano suggests, "In the case of interFIRE I use the example of the left and right front legs of the couch. They clearly show patterns that, when explained, provide practical and tangible information—depth of char—on how an expert's opinion is formulated." These two legs of the couch clearly show that the fire was more intense at the western end of the couch near the "right" (as you face the couch). This allows the investigator to show some of the information on which they based their opinion as to the fire origin.

Forensic Comparisons

The presentation of key forensic evidence often requires demonstrative aids like photographs and/or the actual piece of evidence. For example, in the interFIRE VR case, the investigator or forensic examiner could bring in a blown-up photograph of the tire track impression, the case of the tire impression, and a photograph of the suspect's tire. The photographs of the impression and the suspect's tire could be annotated with arrows pointing to the unique features that caused the examiner to determine that tire caused the impression. Then, the witness could easily and graphically show the jury how they made the determination.

Blow-Ups of Document Evidence

Document evidence in a fire case often includes financial records and insurance records. These records can be complicated and "red flags" are often buried in other data. To assist the jury in following the explanation of financial records, blowing up and mounting certain areas of a document may be helpful.

Bob Corry sees a definite advantage to this demonstrative aid, "Insurance records can be hard for the jury to follow because they often involve unfamiliar terms. Blow ups of insurance policies, bank statements, and the like can be used by the investigator to graphically illustrate a liquity problem or false statements made to the insurance company. There's no substitute for 3 inch high letters in a sworn document that directly contradicts the suspect's statement."

In the interFIRE VR case, two examples of document evidence that could be mounted for jury presentation are the insurance note on coverage knowledge that contradict's Steven Roberts' signed statement and Roberts' bank records showing numerous overdrafts and negative balances.

Visual Investigative Analysis Charts, Link Analysis Charts, and Telephone Toll Analysis Charts

These types of crime analysis charts can help the investigator understand the events in the case, and make those events, and their relationships, clear to a jury. Visual Investigative Analysis (VIA) was first designed in the mid-1960s by the Los Angeles Police Department as a way for investigators to understand the sequence of events in a case, how those events interacted, and identify gaps that required further investigation. The value of VIA charts at trial has now been recognized because they help the jury quickly understand the case. In the interFIRE case, a VIA chart would plot the activities of all the people connected to 5 Canal Street on that morning: Steven Roberts (landlord), Paul and Ruth Thomas (tenants), Meghan Branigan (papergirl), Daniel Mezzi (jogger), Mary and Tasha Gilbert (neighbors), Martin Wakiza (neighbor), Lily McCray (daughter of tenants), and Doron Ingram (boyfriend of Tasha Gilbert).

Link Analysis Charts are diagrams that show the relationships between people, businesses, and organizations. In cases where there are complex business relationships, family bonds, or criminal associates, Link Analysis can help the jury keep track of who's who, who knows who, how they are related to each other, and what the nature of this relationship is, and the degree of certainty with which these people are connected.

Telephone Toll Analysis charts telephone call records as a pattern of activity between entities (persons, organizations, and locations). Most commonly, telephone toll charts are an investigative tool to help law enforcement understand the criminal activity around the target. However, they may be of assistance at trial to help the jury understand the communications between parties involved in the case.

The process of creating these resources is beyond the scope of this article, but for more information on how to create VIA Charts, Link Charts, and Telephone Toll Analysis Charts, consult the resource Crime Analysis Charting by Jack Morris (The Palmer Press, ISBN 0-912479-01-9).


Video can assist the jury in understanding the scene. Video taken by investigators is another way of recording the scene and can help the jury "walk through" the scene. Other videos, as dictated by the case, may help make specific points. In some cases, as allowed by the rules of evidence, reenactment videos can show the jury how the investigator put the facts of the case together into a scenario and demonstrate how that scenario occurred.

One example of a type of video that may be helpful at trial is a video made of the home pre-fire, such as a family Christmas or birthday video. A tape like this can help establish the pre-fire location of contents in the room of origin, which is an issue in the 5 Canal Street fire. Some items in the living room are not where the tenants remember leaving them, raising the question of how they got moved, why, and by whom. Click here to see a video made by the Thomas family before the fire for insurance purposes. At trial, the investigator might play the video, then use an investigative post-fire video of the home to show where the items were found after the fire.

Architectural Models

Scale models can help the jury understand the physical layout of scene in three dimensions, assisting them in spatially relating events, evidence, and indicators. Joseph Toscano notes "These models can get quite elaborate, especially in complex investigations involving loss of life or large monetary loss. They are a very effective tool to educate a jury about the entire investigative process." These models can also be referred to by other witnesses in the case and gives the jury a common frame of reference as they evaluate the evidence and testimony. In the interFIRE VR case, an architectural model would help the jury see how the investigator "plotted" the route the perpetrator took into and out of the scene by linking the evidence he left behind (tireprint, water bottle, bag, moved items) and the accelerant residue samples collected.

Fire Modeling and Test Burns

In some cases, fire modeling and video of test burns may be appropriate. Although these types of items may be judged to have too wide a margin of error to be admissible at trial, the investigator should consult the prosecutor about their potential and whether or not they apply to the case.


Demonstrative aids help the jury and the judge understand the physical evidence and testimonial statements the investigator evaluated. Work with the prosecutor to determine how to best illustrate the evidence in your testimony. Then, to the best of your ability, create demonstrative aids that provide a clear picture of the case. And, don't get caught up in thinking demonstrative aids have to be elaborate. What matters is that they illustrate the point and get it across to the jury effectively. Toscano recalls, "I have watched Dr. Henry Lee, who I consider one of the best expert witnesses in the business, captivate a jury using a glass of water spilled on a table and then slapping it with his hand and telling the jury 'now let me explain what just happened.' He was explaining blood spatter evidence using only a glass of water."


The author gratefully acknowledges the substantial contributions Joesph Toscano and Robert A. Corry made to this article.

1Robert A. Corry: Biography

Robert Corry is the principal investigator for Forensic Investigation & Technical Services LLC, a private investigation firm licensed in Massachusetts and Connecticut specializing in fire and arson investigation, large loss fire investigations and investigation skill training.

He was an Assistant Vice President and Fire Investigation Specialist at American Re-Insurance Company from 1997 to 2002. His responsibilities there included consulting with primary property insurance carriers on large loss fire, arson and explosion claims and providing educational programs on fraud and arson investigation & defense.

Bob was on the Massachusetts State Police from 1974 until his retirement in 1997. In 1981, he was assigned to the Massachusetts State Fire Marshal’s Office assisting 26 urban, suburban and rural communities perform fire and explosion investigations. He was among the first Accelerant Detection Canine handlers in the United States.

From 1992 to his retirement he was Detective Lieutenant and Commanding Officer of the Mass State Fire Marshal’s statewide Fire and Explosion Investigation Unit – the largest unit in the state police.

Noted for helping to solve hundreds of fire investigations, Bob has taught in national FBI, ATF and U.S. Fire Administration programs as well as in many state and international fire investigation training programs. In 1993, the U.S. Fire Administration designated the Lawrence, (MA) Arson Task Force which he commanded as the national model. The National Fire Academy’s 2-week residential program, Management for Arson Prevention and Control, is based on this unit.

He was the principal writer for A Pocket Guide to Accelerant Evidence Collection, recommended as a reference in all editions of the Guide for Fire and Explosion Investigations, NFPA 921 and Kirk’s Fire Investigation 5th Edition. He was a member of the principal development teams for several national level fire/arson investigation training programs including interFIRE VR and Motive, Means and Opportunity.

A Life Member of the Massachusetts Chapter, IAAI he served as the organization’s President from 1988 until 1990 and is currently on the Board of Directors. He is a member of the NFPA. Bob earned a BS in Criminology from Northeastern University and a MS in Criminal Justice Studies from American International College.

He served in the U.S. Army from 1966 through 1970, where his last assignment was Captain, 173rd Airborne Brigade in Vietnam. He has been married for 30 years and has three children.

2Joseph Toscano: Biography

Joseph Toscano has been involved in all aspects of the field of fire investigation and case management for the past twenty-five years. He is an internationally known lecturer and author on effective investigative techniques and solutions for the Insurance Industry, Law Enforcement, Fire Service and Legal professions. His expertise includes Fire Origin and Cause, Large Loss Investigation Management, Curriculum Development, Claim Division and SIU Training, Subrogation and Fraud Investigation. Toscano also pioneered the utilization of K-9’s as a tool in the investigation of fires.

Toscano begin his career as an appointed police officer in East Haven, CT, and was promoted through the ranks to Police Inspector, Arson Control and Assistance Program, Division of Criminal Justice, State of Connecticut assigned to the States Attorneys Office New Haven. In 1993, after a long career in law enforcement, Toscano moved to American Re-Insurance as Appointed Director, Claims Division, Fire Investigation Specialist, American Re-Insurance. Throughout his ten years with American Re, he was promoted to Assistant Vice President and then Vice President of the same division. Currently, Toscano is a Consultant, Fire Investigation Specialist, Fire Investigation & Litigation Support, for Chilworth Technology.

Toscano holds many professional distinctions. He is a longtime member of NFPA's Fire and Explosion Technical Committee (NFPA 921), a past member of the Board of Directors for the Insurance Committee for Arson Control, and Past President of the Connecticut Chapter International Association of Arson Investigators. Toscano is a member of NFPA, IAAI, the Connecticut Fire Marshals Association, and the International Association of Special Investigation Units.

Toscano is a course developer and instructor in all four State and Local Fire Investigation Training programs developed and delivered by the Bureau of Alcohol Tobacco and Firearms at The Federal Law Enforcement Training Center in Brunswick, GA since 1980. He is also an instructor at the Trial Advocacy Center in Columbia, SC for the National District Attorneys Association/National College of District Attorneys Arson Investigation Training Program. Toscano has been an adjunct professor or guest lecturer at the following: University of New Haven, Fire Science Program and the Yale University School of Law, prosecution intern program. Toscano has lectured regularly throughout the United States since 1980 to the following Organizations: ICAC, IAAI, IASIU, PLRB, NCDA, ABA, CPCU, ATF, NDAA, USFA, IFM, NYFD, NICB, and Police Foundation National Institute of Justice. Toscano developed and produced "Motive Means & Opportunity" a comprehensive fire investigation training program in English and Spanish for worldwide distribution, and interFIRE VR, an interactive CD-ROM fire investigation training program in a partnership with The United States Fire Administration, Bureau Of Alcohol Tobacco and Firearms and The National Fire Protection Association. Toscano also developed "Abandoned Building Project Tool Box" in partnership with The United States Fire Administration, International Association of Arson Investigators and The Insurance Committee for Arson Control. Toscano has developed and delivered a broad spectrum of educational programs on various fire investigation topics in the following countries: Australia, Taiwan, Great Britain, South Korea, New Zealand, Panama, Chile, France Holland, Belgium, Canada and Spain.

Toscano has been honored with Investigator of the Year Award (IAAI, 1990), "Lecturer of Merit Award" (National College of District Attorneys), "Arnold Markle, Distinguished Service Award" (University of New Haven), "Hammer Award" presented by Vice President Al Gore for efficient use of government funds in the development of interFIRE VR (1999), Honor Award (Bureau of Alcohol Tobacco and Firearms, 2001), Distinguished Service Award (New York City Fire Department, 2000), and numerous awards and commendations for meritorious police service.

Toscano holds a B.S. from Southern Connecticut State University, New Haven, CT. He is a Certified Fire Investigator (CFI), International Association of Arson Investigators, and recognized as an "expert witness" in both State and Federal courts.

This article appears courtesy of Munich Re America, Inc. formerly American Re-Insurance Company.

Home | interFIRE VR Support | Training Calendar | Training Center | Resource Center | Message Board | Insurance Info
Sponsorship Opportunities
Web Site Designed for 800 x 600 by Stonehouse Media Incorporated® Copyright © 2024 All Rights Reserved.