Archive for March, 2012

by: Jason A. Sutula

Computer Fire Modeling Image

Now that some of the basics of what it means to be a fire investigator, how to become one, and knowledge requirements have been discussed in this blog, I want to present a case study of one of the more well-known investigations. This blog post may be substantially longer than my previous posts, but it is a great segue into some of the most critical issues facing the field of fire investigation and providing sound analysis as a fire expert. This is the story of Paul Camiolo.


A fire occurred in a residential structure in the early morning of September 30, 1996.  At the time of the fire, three people were in the residence, two parents (age 81, male and age 57, female) and their adult son (age 31).  The two-story house was composed of typical wood frame construction, and was built in approximately 1971.  The 1st floor included a living room and dining room in the front of the house and a family room, kitchen, and den/storage room with an adjacent bathroom in the rear of the house.  The 2nd floor had four bedrooms and one bath.  The master bedroom was at the head of the stairs on the second floor.

The family room, which was situated in the back, left portion of the first floor had a brick fireplace along the south wall and plywood paneling along the other three walls.  A substantial fuel load was present in the room at the time of the fire.  The fuel load included a three-cushion couch along the east wall, a two-cushion love seat along the west wall, and a lift-type recliner chair near the north wall by the doorway to the kitchen.  In addition, there were several small tables and a television.  The family room also had wall-to-wall carpeting over the original hardwood floor.

The fire was first reported via 911 by the Paul Camiolo at 4:30 a.m.  The first person to respond to the emergency call was a police officer who arrived at the scene at approximately 4:35 a.m.  Paul met the officer on the north side of the residence.  They proceeded to the south side of the house.  The officer reported that the large bay window on the southeast corner of the house had broken out and flames were venting through it.  The officer found Paul’s mother on the back porch at the southwest corner of the house.  Paul’s mother was found conscious and alert but suffering from burns to her hands, upper body, and head, including singed hair.

The first fire department units arrived at approximately 4:40 a.m. and the fire was declared under control at 5:03 a.m.  A fire department search of the house found Paul’s father unconscious in the bathroom in the right rear of the first floor near the back door exit to the porch. He was later pronounced dead. Paul’s mother was treated at the scene for burns and smoke inhalation and then transported to the hospital.  After initial treatment in the emergency room, she was transferred to the Burn Unit of a second hospital.  She ultimately died several months after the event from complications related previous health conditions and injuries sustained during the fire.  Paul was also transported to a hospital and was treated for burns and smoke inhalation and then released.

An autopsy performed on Paul’s father revealed that he had non-lethal burns to his head and upper torso and had suffered smoke inhalation. His cause of death was listed as smoke inhalation as a result of carbon monoxide poisoning.  Paul’s father’s carboxyhemoglobin (COHb), or the percentage of total hemoglobin in the form of COHb in the blood, was reported as 45%.  Incapacitation of a victim due to carbon monoxide poisoning typically occurs with COHb greater than 30 percent, and death usually occurs above 50 percent, though research has shown that both incapacitation and death can occur at lower percentages than those listed above.

Police and fire officials conducted a cause and origin investigation.  Their investigation determined that the fire originated in the family room in the left rear of the first floor.  Examination of the scene revealed heavy burn damage to most of the furnishings in the family room.  Heat and smoke damage was observed throughout the rest of the house with some fire extension into the kitchen and hallway adjacent to the family room.

Further investigation of the burn damage in the family room showed substantial damage to the couch, the love seat, and the lift chair.  The greatest damage to the couch was at the north end (toward the kitchen) with damage decreasing toward the south end (toward the fire place).  A similar damage pattern was noted on the love seat including greater damage high up on the back of the love seat.  The lift chair showed greatest burn damage to the east (toward the couch).  The wood paneling and studs behind the couch showed damage beginning behind the north end of the couch with a “V” pattern toward the south (fireplace).  In addition, the carpet in the center of the room was heavily damaged including a substantial area where the carpet and padding had been consumed in the fire, revealing the hardwood floor underneath.  The hardwood floor showed irregular discoloration in the center of the room where the carpet had been completely burned.  Because of the irregular pattern on the hardwood floor, samples were taken of the carpet, padding, newspaper (used between the padding and the hardwood floor to stop squeaks), and floorboards by fire investigators and sent to a laboratory to test for the presence of flammable or combustible liquids.

Paul’s Story

Paul was interviewed by investigators and gave the following account of the fire.  He stated that his mother had gone to bed at approximately 8:30 p.m. on the night of the fire.  His father subsequently went to bed at about 11:30 p.m.  Paul fell asleep watching television in the family room, woke up about 2:30 a.m., and went to his bedroom.  He was awakened at just before 4:30 a.m. by his father’s call for help from downstairs.  He went downstairs to the family room in response to his father’s call and discovered his father in his lift chair and his mother on the couch.  Upon entering the family room, he observed his mother attempting to pat out a small fire on the couch with her left hand.  He immediately went to the kitchen and got a pitcher of water.  When he returned to the living room, he attempted to extinguish the fire with the pitcher of water but found that it had little effect on the fire.  He advised his parents to get out and quickly retreated to the dining room to call 911.  While on the 911 call, he observed his parents traveling across the kitchen toward the den/storage room (in the direction of the rear exit) as the fire continued to grow.  Upon completion of the 911 call, he left the house through the front door.  After retrieving some sweatpants from his car (he was originally wearing only a pair of boxer shorts), he went to the rear of the house to meet up with his parents.  When he arrived at the back of the house neither of his parents were visible.  He opened the rear door and found his mother on the floor inside the door.  He dragged his mother outside onto the porch but could not enter further to find his father because of the heat and smoke.  He then went to the front of the house to await the arrival of emergency personnel.  He met a police officer and accompanied the officer around back to his mother’s location while advising the officer that his father was still in the house.  Eventually, the son was taken to the hospital and treated for his smoke inhalation and burn injuries.  The son suggested that the fire started as a result of his mother’s mishandling of smoking materials.

The Fire Investigator’s Hypothesis

Based on the burn damage to the residence and the Paul’s statement, the investigation focused on the area near the north end of the couch.  A lamp in this area was eliminated as a possible cause of the fire when an examination of the lamp and the adjacent outlet revealed no evidence of damage consistent with initiation of a fire.  The careless use of smoking materials could not be eliminated based on the burn damage, the statements of Paul, and evidence of other smoking materials throughout the 1st floor.  Other possible accidental causes of the fire were eliminated.  Initial investigation reports concluded that the fire was accidental as the result of careless smoking or improper disposal of smoking materials.

Some samples of fire debris were taken and sent to the state crime laboratory. The laboratory report showed that the samples of carpet, padding, and newsprint obtained from the room of origin were negative for common ignitable liquids, but the floorboards of the room of origin did test positive for trace amounts of weathered gasoline.  After receiving this report, the fire investigator changed his fire investigation report to conclude that the fire was intentionally set by Paul through the use of gasoline as an accelerant.  The motives given for the Paul’s actions were that he wanted to collect the assets of his parents, and that he no longer wanted to provide physical care for them.

The fire investigator developed the following account of the fire.  While Paul’s parents were upstairs in bed, he spread a gallon of gasoline on the carpet in the family room.  He ignited the room on fire, grabbed the cordless phone, ran to the front door, went outside and shut the door, and waited for his parents to wake up.  When they had been alerted to the fire, he called 911 from outside the house, held the door shut as his parents came down the stairs, and forced them to traverse the house to the rear of the building where they succumbed to smoke inhalation.

Computer Fire Modeling as a Means to Reconstruct the Fire

After examining the available data, it was determined that a computer fire model could be employed to determine which of the two competing scenarios was more likely to occur.  The lead fire investigator insisted that the fire was a result of Paul pouring gasoline in the family room, while Paul maintained that the fire was the result of an accident.

The geometry was first constructed in the fire model to form an accurate three-dimensional representation of the structure of the house.  After the geometry had been completed, the initiating fire scenarios were placed into the model.

The fire scenario in the accidental case was initiated by a small heat release curve placed on the couch in the family room simulating a small flaming match dropped on the couch.  The curve allowed a short fire exposure to ignite the surrounding couch structure and grow from that point.  The following figure depicts the resultant convective heat release rate modeled during this fire scenario.

The fire scenario in the incendiary case was initiated by an area of gasoline igniting, burning, and spreading quickly over a large surface area located on the floor in the middle of the family room.  The following figure shows the resultant convective heat release rate for the incendiary fire scenario.

Results and Discussion

The computer fire models produce various resultant quantities that can be analyzed for each scenario to determine which scenario is most consistent with all of the facts in the case. In the accidental case, the greatest interest is how the time to reach untenable conditions “fits” with the story provided by Paul.  In the incendiary story, again of greatest interest is how the time to reach untenable conditions “fits” with the story proposed by the fire investigator.  To decide which scenario is most consistent with either of the two proposed hypotheses, a quantity of data must be chosen to analyze such that a determination between the two scenarios can be made (i.e. temperature).

The above figure shows a temperature time curve for the conditions present within the family room during both the accidental fire scenario and the incendiary scenario.  When the couch is burning due to the accidental scenario, the fire grows relatively slow and the temperatures within the room increase slowly over time.  Conversely, the temperatures for the incendiary fire spike early in the fire and slowly subside.  This indicates a strong difference in the resultant fire conditions from each fire scenario.

Examining the accidental fire and the data, the question must be answered as to whether or not the temperature within the family room over a period of time is tenable enough for the Paul’s story to make sense.  Paul claimed that he observed his mother trying to pat out the fire with her left hand early on in the fire growth.  This is consistent with temperatures early in the fire caused by a small fire on the couch and is consistent with the burn injuries observed on his mother’s left hand.

Over the first 200 seconds of the accidental fire scenario, the temperature in the family room does not exceed 200 oC (392 oF).  It can be determined then, for the accidental scenario, that for the first three minutes of the fire, Paul would have had time to respond to his parent’s call for help, attempt to put the fire out with a pitcher of water, call 911, urge his parents to leave the residence, and exit the house through the front door.  The fire growth and tenability for this scenario is consistent with the story given by Paul.

The incendiary scenario created by the fire investigator indicated that Paul poured gasoline throughout the family room, lit the room on fire, and exited the building through the front door.  The temperature-time graph above clearly shows that Paul would have to have been moving very quickly to exit the residence without receiving significant burns.  The fire investigator also specified that the parents were on the 2nd floor asleep in their bed at the initiation of the fire.  In order to explain the parents being found where they were after the fire, the investigator states that the parents awakened at some point, moved downstairs, could not open the front door, headed to the back door, and were found near the rear of the structure without severe burn injuries.  For this to occur, the incendiary scenario must allow for temperatures cool enough to allow the parents to traverse the house over the course of a few minutes without being burned.  The results of the computer fire modeling as seen in the above figure indicate that conditions would have been severe enough to cause burns within the first 20 seconds after ignition.  The following figure shows the temperature versus time in the front hallway near the stairs and the front door.

The above figure also clearly demonstrates that the temperatures within the house quickly become untenable in the incendiary case. For the incendiary scenario, if the parents were indeed in their bed asleep when the fire was lit, they would have succumbed to the fire upstairs in their bedroom.


When conducting a fire investigation, reconstruction, and analysis, it is extremely important to gather as much data about the incident as possible.  In this case study, a computer fire model was used to compare two competing scenarios.  The majority of the data obtained, such as the burns on Paul’s mother’s left hand, the location of Paul’s mother and father within the residence during the fire, and the Paul’s lack of serious injury supported the Paul’s account of the fire.  Only the presence of gasoline found within the floorboards of the family room provided the fire investigator with weak evidence supporting an incendiary fire cause.  A qualitative analysis of each scenario using computer fire modeling determined that the incendiary scenario was implausible based on the resultant fire conditions within the residence.  It also led to the reexamination of the laboratory test results for gasoline.  Additional testing revealed that Lead was present within the gasoline found in the floorboard samples.  This discovery dated the gasoline to having been in the floorboards for over a decade prior to the date of the incident and eliminated the fire investigator’s proposed scenario.

This particular case study demonstrates just how powerful computer fire modeling can be when used in fire forensics. When computer fire modeling is combined with a thorough origin and cause analysis of a fire incident, it can be considered an extremely effective and powerful tool for fire investigators. This tool has the power to explore multiple fire scenarios quickly and cost effectively. Over the last decade, the use of computer fire modeling in forensic analysis has increased dramatically. With the continued rapid expansion of processing power, storage, and memory, the use of computer fire modeling will become a requirement for truly understanding what happened in a fire incident.

Without the use of computer fire modeling in this particular case, Paul Camiolo would have been falsely accused of killing his parents through arson, convicted, and punished for a crime that never happened. Few tragedies can compare to losing loved ones in an accident and then being accused of their murder. In this case, science prevailed.


by: Jason A. Sutula

Jumping right back in from the previous post, the remaining topics as outlined in NFPA 1033 – Standard for Professional Qualifications for Fire Investigator are:

10. Fire Investigation Methodology
11. Fire Investigation Technology
12. Hazardous Materials
13. Failure Analysis and Analytical Tools (List from Section 1.3.8 of the 2009 NFPA 1033)

Topic Number 10, Fire Investigation Methodology is, in essence, the sum total of NFPA 921 Guide for Fire and Explosion Investigation. My personal goal in this blog is to dedicate at least one post if not more to describing the nature of NFPA 921 and how it lays much of the groundwork for conducting a sound fire investigation. In general, though, a fire investigation  methodology is the process by which the investigation is conducted. In almost all circumstances that arise from fire investigation that lead into fire expert work in the legal field (i.e., in both criminal or civil cases), the methodology by which a scene is investigated and the methodology by which a fire investigator comes to his/her conclusions is one of the most (if not THE most) important and significant issue.

The topic of Fire Investigation Technology encompasses the rapidly advancing technological tools that can be utilized in the field. This can included still-photo digital camera equipment, video documentation equipment, laser measuring devices, 3-D laser scanning equipment, in-field laptop computers, high-powered computer servers for running computer fire models, and even smart-phones with appropriate applications. While not all of these particular examples need to be utilized for every fire investigation, an investigator needs to be aware of the various tools available and when they need to be implemented in a particular case.

A risk at any fire or explosion scene is the presence of potentially hazardous materials. This is especially true when investigating fire in commercial or industrial applications, but hazards can and do exist in smaller residential settings. For example, industrial settings can involve the storage, leakage, or fire involvement of various chemicals. In fire or explosion investigations where chemicals are involved, special training may be required to even set foot on the scene. Certainly in these hazardous environments, personal protective equipment (PPE) will be required to perform the fire investigator role. Another example in the residential setting could be the presence of Asbestos, which would have to be mitigated or removed concurrently with the processing of the scene.

Finally, we have arrived at Topic Number 13, Failure Analysis and Analytical Tools. This is also a fairly broad topic that is related to the ability to use analysis and logic to deduce how a particular failure would occur and if it could have been responsible for initiating or contributing to the growth and spread of the fire. In industrial settings, a failure analysis is typically conducted BEFORE any loss occurs to determine the level of risk associated with  a particular process, system, or plant. The methodology behind conducting a failure analysis does not change whether it occurs before a fire or explosion loss, or after it. When conducted before a loss, the hope is that any risk discovered during the assessment can be mitigated such that the chances of a loss occurring are greatly reduced. In general, it is far less expensive for a company to purchase a risk analysis service for their facility prior to a problem than it is to suffer a fire or explosion event.

We have made it through all the topics in the field in which every fire investigator needs to be knowledgable. The various paths that lead to becoming a fire investigator provide the opportunity to gain the required knowledge in all of these topic areas. In should be recognized though, that not all of the paths to becoming a fire investigator will provide a detailed understanding into all of the topics. It is up to each fire investigator to attend continuing education to fill in areas where their personal knowledge base has gaps.

One way to do this is through the two main certification organizations in the US for fire investigators. These organizations are the National Association of Fire Investigators (NAFI, and the International Association of Arson Investigators (IAAI,

NAFI has been providing certification to fire investigators since 1982 through their National Certification Board. In addition to providing a means of certification, NAFI also conducts training seminars throughout the year. The various certifications available through NAFI are Certified Fire and Explosion Investigator (CFEI), Certified Fire Investigation Instructor (CFII), and Certified Vehicle Fire Investigator (CVFI).

The IAAI began providing certification to fire investigators in 1986 though the National Board of Fire Service Professional Qualifications. Similar to NAFI, the IAAI conducts training seminars throughout the year. The main certification available for fire investigators is the Certified Fire Investigator (CFI). Also available is the Certified Instructor (CI) for those who wish to train other investigators.

Both organizations offer membership, which includes various services for a nominal yearly fee. Most importantly, each organization provides a jobs board to help job seekers find a position in the field of fire investigation.