When it comes down to a fire investigation the most important role for all agencies to be a part of is that of a single unit/team. This is primarily due to the fact that the second one agency becomes non-compliant or difficult the case will come to a swift stand still as each agency requires the other equally in order to get the case moving. Some agencies are more vital than others depending on the specifics of a case however, every agency is still involved and is still crucial to a successful prosecution.
Police are required to not only coordinate the investigation but to also: secure the scene to preserve evidence and prevent contamination from the public/media/other officer/etc, obtain potentially crucial evidence from witnesses which may highlight a suspect/highlight potential leads, follow leads in order to obtain evidence to build a case, carry out search and seizures in/of properties (with a warrant) to use as evidence. All of which other agencies require to move on with the case but can't obtain themselves as they do not have the legal ability to do. If any other agency attempt to then it would be a breach of the suspects/victims legal rights and not only would there be no chance of prosecution or payout to the victim but the agency would be investigated as well as probably sued for their breach of the law.
Scenes of Crimes Officers are expertly trained in the preservation, protection and collection of evidence and in turn will be the ones to strategically collect the evidence that will later be relied on in court. No other agency has the proper training in order to retrieve the evidence without contaminating or damaging it and even if they managed not to barristers would have a field day with it in court because at no point can it be proven that the evidence wasn't contaminated or damaged as it wasn't collected by a trained professional. In order to collect the evidence every agency needs to do their part in the case it has to be collected by SOCO's as without them a case couldn't successfully be made in court to prosecute.
Specialist Dog units are one agency that may necessarily not be needed in every single case as some easily identifiable accident/natural cases of fires don't need a cause of the fire to be sniffed out as it will already have been identified. The Dog Unit is still crucial in arson cases as some of the more experienced dogs can identify over thirty different fire accelerants where it would require a Forensic Scientist to do potentially multiple advanced techniques in order to identify the accelerant. In a lot of cases the accelerants presence isn't particularly easy to identify straight away so SOCO's may overlook the possibility of one being present without the Dog Unit. If evidence were to be missed an arson case may be overlooked an merely seen as an accidental fire meaning that the offender who started the fire would have the opportunity to start another fire as that is a common occurrence with arsonists as they thrive from the chaos of the investigation. If another fire is started then any life lost at the second fire would be the result of poor investigative skills and the lack of the Dog Units presence. The Dog Unit will liaise with SOCO's to ensure that evidence the dogs find isn't overlooked.
Forensic Scientists are required to liaise with SOCO's and police to ensure the successful hand over of evidence collected from the scene. Forensic Scientist teams use their expertise to further analyse evidence gifted to them from the scene to provide factual evidence on everything from DNA matches to specific suspects to chemical residue from the scene being on the suspects shoe. Without the detailed evidence that is found within a forensic laboratory there wouldn't be substantial evidence to provide in court for a successful prosecution therefore the case would be thrown out letting the suspect free. The information forensic experts gain is useless without them as nobody is educated on their findings to the same extent of expertise they are therefore without a Forensic Scientist standing as a expert witness in court explaining to the jury what they've found the jury wouldn't be able to understand the evidence provided or its meaning therefore they couldn't use it to make a decision on the guilt of the defendant. This would mean all the agencies wouldn't be able to prosecute without a Forensic Scientist in the case and without SOCO's there is no evidence for a Forensic Scientist to do their part in a successful prosecution.
A Pathologist is another member of an agency that is only required under certain circumstances usually when there's a deceased corpse at the scene of the incident. The Forensic Scientists requires the pathologists post mortem/autopsy report in order to determine whether or not any of the evidence they have been provided correlates to the case; a knife matching a wound or a fire accelerant in the burns matching one found at the scene. The police/fire investigators require the reports in order to determine whether the case is murder, suicide, natural, or suspicious before they can begin an investigation.
Gas and Electrical Advisers are required in almost all cases to completely rule out the potential for accidental fires. They both work with the Insurance Loss Advisors in any fire case and in turn all three parties require each others cooperation in a fire investigation so as to ensure the case is dealt with efficiently. Should their investigation find potential for fraud or criminal circumstances then the police will join the investigation along with almost every other agency.
Health and Safety Executives are required, during the fire investigation, to liaise with every agency involved and to assess the scene before entry to the premises post fire so as to ensure no further loss of life or casualties occur. The advisory role is required so as to insure the investigation runs smoothly without risking the lives of anyone in the agencies involved.
At a fire scene it is important to not that no one agency is in complete jurisdictional control meaning that the agencies must work hand in hand to avoid conflict and ensure a successful, swift case whether it lead to legal prosecution or just a benefit claims payment so that anyone involved can get back to their lives hassle free. Agencies are free to collaboratively organise a system of investigation usually organised between police and fire services taking into account the advice of the other agencies involved. Agencies who do not agree with the system of investigation being set out by the police and fire services are free to negotiate a way around their problem with it.
