Assessment? Who is the Forensic Engineer and what is his Role?
3.2 Forensic Engineering
Recalling Noon in [10], forensic engineering is the application of engineering principles, knowledge, skills, and methodologies to answer questions of fact, usually associated with incidents,
catastrophic events, and other types of failures, that may have legal ramifications. In short, the job of the forensic engineer is to answer the question “what caused this event to happen?”, knowing only the end
result and applying reverse engineering. The final result of the forensic engineer's job is the reconstruction of the incident, that is to say the full explanation about the incident that has been solved. To do so, failure analysis and root causes analysis are used. The reader should be now aware of the difference between the two definitions, even if they are sometimes used interchangeably. Familiarity with codes, standards, protocols and usual work practices is also required. There are also several guidelines promoted by different organizations that suggest how to conduct forensic investigations depending on the type of incident. The main duties of a forensic engineer include:
To assess the conditions before the event;
to assess the conditions during and after the event;
to hypothesise how the pre event conditions become the post event conditions;
to search for evidence that supports or falsifies the proposed hypotheses; and
to apply the scientific method and the engineering knowledge to link facts and observations, thus reconstructing the incident.
Those activities are always conducted with an extensive and constant application of logic, which provides order and coherence to all the facts, principles, and methodologies used.
An incident investigation usually requires a multidisciplinary approach. This reflects also on the forensic engineer, who is not a specialist in a given engineering discipline. On the contrary, several scientific disciplines are involved in the solution of forensic
engineering problems. When reconstructing the incident, a discipline may give its contribution to developing a further step in the overall reasoning, and so on. From this point of view, a skilled forensic engineer is usually an excellent engineering generalist.
The forensic world is both shrinking and expanding, as M.M. Houck said in the preface of [6]. The global scenarios are responsible for this double trend: on the one hand, forensic experts travel around the world no longer limiting their profession within a laboratory. On the other hand, the increased interest in the topic led to a growing
knowledge in size, complexity, and depth. The role of forensic engineering in the recent investigation is doubtless predominant, especially when talking about industrial accidents. The main reason for such a success is based on the rigorously adopted approach, previously discussed, that allows treating forensic engineering as a discipline. In Europe, forensic engineering is a new discipline: it is sufficient to run a search on the internet to find how low the level of related contents is. The same conclusion cannot be considered for other disciplines; for instance, an extended set of information about legal medicine, like definitions, classifications, and scopes, is already available to the community. The scientific community widely
recognises the legal medicine all over the world, while the forensic engineering has experienced a lower trend in Europe (not in the US and in the Anglo Saxon world, where significant funds have been provided to support the investments on this field).
Talking about forensic engineering implies the application of the techniques, i.e. the principles and the methodologies typical of
engineering, aimed at the resolution of complex problems, dangerous events claimed during a judicial proceeding, thanks to the role of the technical consultant (who serves the judge or the prosecutor or one of the parties). Forensic engineering consists of a complex match
between engineering, intended in all its different sectors (including industrial, structural, chemical, mechanical, electronic, and electric engineering), and law, in trying to use a comprehensible language to support who is in charge to make judgment. Obviously, such a
transversal topic is complex and vast. The intent of this book is to provide an organic approach to this immense complexity, in order to develop a technical investigation related to industrial accidents.
The activities of the forensic engineer are removed from the events that he/she is trying to reconstruct. Time passes in one direction, and some details, useful to have a complete reconstruction, are left behind.
What remains are traces, that is to say only partial evidence is provided to the forensic engineer, who can enjoy only a necessarily incomplete and occasionally vague knowledge. Therefore, the goal of the forensic engineer is to connect those dots, trying to reconstruct the actual sequence of events that leads to the unwanted incident.
Sometimes data could be part of a too large population or they could be too unwieldy to measure directly. In these cases, statistics and probabilities are the tools to obtain a robust and wide base of the investigation pyramid. Facts are put in sequence using logic and scientific rigours. If an event comes always after a specific fact, then this is often the proof that the prior caused the latter. However, this is not absolutely true: coincidence, correlation, and causation have
different values and a forensic engineer has to look for causation only in his/her reconstruction activities. These concepts are discussed in depth in Chapter . Causation is not only a scientific requirement but also a legal necessity: indeed, the cause effect relationships are the fundamental basis to establish not only the actual incident path but also the eventual legal accountabilities.
When an incident occurs, regardless of the risk based process safety or any other prevention loss strategy, tragic losses of life, property,
reputation, and treasure are experienced. It is therefore normal,
especially for those people who are directly affected by such losses, to ask why it happened. Therefore, the forensic engineer covers a delicate role when carrying out the investigation, and he/she must not allow biases to affect the logic and the proven scientific principles, otherwise he/she will likely fail. Practice is undoubtedly the best way to become a good investigator. However, studying the available literature gives you a discount on the amount of time required to be proficient. This is the goal of this book, also allowing the reader to learn from others'
experiences and mistakes.
Forensic engineering is a discipline. Possessing the basic scientific knowledge cannot be substituted by the mere application of an
investigation method, since the methodology is simply the framework to organise and assess knowledge, evidence, and facts. The application of the scientific method to determine a root cause cannot be the mere shift of the laboratory methodology to the context of actual
investigation. Indeed, in a laboratory experiment, variables are studied whilst being free from other influences, without needing to consider the simultaneous presence of other elements and with pre defined and controlled boundary conditions. This approach, in theory, could also be applied to industrial accidents, to reconstruct the real sequence of
events. This means that, in theory, variables are changed and combined until the combination leading to the experimental
duplication of the event is found, thus solving the investigation case.
However, this approach has many problems. Firstly, each industrial incident is unique: varying and combining variables until they
perfectly match the event being assessed is costly, time expensive, logistically difficult, and risky for safety too. However, a large collection of facts and observational evidence can be seen as a
substitute for the direct experimental data. This is generally true, but only the correct reconstruction hypothesis will fit them, being also scientifically rigorous. An example is the determination of an equation from a set of points on the Cartesian plane: the larger the number of points, better the fitting curve. Therefore, the application of the scientific method for the reconstruction of accidents and failures consists in:
Proposing a first working hypothesis, based on first verified information;
modifying the first working hypothesis as more information is collected, to fit the observations progressively gathered; and testing the working hypothesis to predict the presence of unobvious or overlooked evidence.
Finally, a working hypothesis is considered the real complete incident reconstruction if:
It encompasses all the verified observations;
it predicts (when possible) the existence of additional unknown evidence; and
it is consistent with the scientific method (principles, knowledge, and methodology).
However, incidents sometimes destroy the evidence and observational gaps are not so uncommon. When few data are available, more than one hypothesis could fit the evidence gathered, preventing a unique solution. It is the consequence of accepting the complex theory in the incident investigation context: knowledge of facts cannot be fully possessed, time is not fully reversible and observational gaps have to
be accepted. This is why the collection of the evidence is a
fundamental part of the accident investigation workflow: only a wide basis of the investigation pyramid results in robust conclusions. In this sense, forensic engineering is like solving a picture puzzle: disjointed pieces may not provide much information, but when they are sorted methodically, they fit in a logical context and the overall picture starts to emerge. Continuing the similarity, when a great part of the puzzle has been solved, it will be easier to put in position the remaining pieces.
Engineering is often seen as an exact science, that is to say there always exists a unique exact solution to engineering problems.
Forensic engineering does not share this peculiarity of traditional engineering [10]. Actually, it has the same “soft” attributes and
uncertainties that affect other disciplines like sociology, economics, or psychology. No matter the engineers' qualifications or experiences: in the context of a court, what is important are the facts that the
engineers provide to the judge and the jury. In this sense, a clear
distinction with the role of the attorney emerges. Indeed, the attorney may have a stake in the outcome of a trial, since its compensation may be a benefit if he/she will win. It is not unusual that the attorney
pressures the engineer to manufacture the technical report in order to gain a better position for his client. While the attorney is legitimated in defending his client, fully representing him in front of the judicial
authority and doing the best to protect him, the role of the forensic engineer is quite different. Even if the commissioner may want to cover some facts, the forensic engineer does his best job when he informs the attorney about all the facts he has uncovered: this also results in providing the attorney with a full awareness about what goes wrong, allowing him to best prepare the case for the presentation in court. Moreover, accepting to cover facts or an extra remuneration to do so, can result in the suspension or the revocation of the engineer's license. This does not mean that the investigator is regarded as neutral to the investigation outputs [16]. Indeed, the position of the
investigator towards the event and his role regarding the investigation results are two aspects that could impact the outcomes of the
investigation. For example, the investigator could be part of the
company where the event occurred and also part of the plant; or could
not be part of the plant and attached to the corporate headquarters; or he could be from outside the company where the event occurred.
Therefore, different positions of the investigator may result in
different outcomes: investigators that are too close to the event may hide or disregard some root causes, because they may not have access beyond the organizational limit of the company to which they belong, thus with no possibility (or authority) to explore potential underlying causes. Or, depending on his position, the investigator may develop a corrective recommendation that he knows to be within the
organizational boundaries available to him. Not only the position, but also the role of the investigator may affect the investigation outcomes.
Indeed, an investigation is rarely launched by the investigators
themselves, but it is often requested by someone having the authority to do it. Consequentially, the information gathered during the
investigation could be filtered by the authority before the release of the investigative report. The higher the investigator's independence, the greater the amount of information released in the final report.
Forensic engineering can be specific or general in scope, depending upon the nature of the dispute [6]. In this sense, the distinction
between a failure analysis and a root cause analysis has already been done. Indeed, while a failure analysis is carried out to determinate how a specific component, machine, or equipment has failed, a root cause analysis concerns the managerial or human performance aspects rather than the failure of a single part, being addressed in preventing the incident from recurring through a deep analysis about how to enhance procedures and managerial techniques. This is why it is usually adopted where there is a heavy emphasis on safety and quality, such as for industrial incidents.