FORENSIC investigation attempts to provide solid evidence-based links that convert a strongly held speculation or a subjectively biased opinion into factual confirmation. Collection of both physical and ‘circumstantial’ evidence at a scene is the traditional basis for demonstrating a time-space continuum … that is, a factual pathway that demonstrates that one piece of evidence is internally consistent and compatible with all other pieces of evidence.

If a significant piece of evidence remains unsupported by corroborating evidence and other plausible evidences have not been examined then it should make the investigator(s) review all aspects of that assessment, including the manner in which the evidence was obtained. The ability of the investigators to have a wide, open and flexible mind is critical to an impartial scientific assessment and is essential in determining the truth.

Searching for the truth should never be an “end justifying the means” process. The research is the way whereby the means justifies the end. It should never be about problem resolution; it is a more open-ended and courageous approach. It should NOT predict or assume what might have happened; it needs to be unprejudiced.

Here’s an historical scenario on just one local incident that received sensationalised media coverage for well over a week.

In May this year an Old Beach resident reported deaths of up to 20 chickens in his backyard coup to DPIW. It was an unusual sudden death of many birds in a confined space.

Question: What caused the death of these chickens?

When it was first reported the description of the incident suggested many likely possibilities. It was an unusual and suspicious incident.

Question: Had the chooks died of a serious disease?; a lighting strike?; an acute poisoning?; a premeditated attack by a deranged human?, or an attack by a dog or dogs?, by a Tasmanian devil?, by a spotted tail quoll?, by a feral cat?, or by a fox?

Question: Were there any other possibilities?

Question: What extra information was needed to confidently dismiss most of these possibilities and confidently accept just one?

We know from the DPIW’s documents that the dead chickens were left as they were found for four days. A ‘barbed wire hair trap’ was constructed through a likely entry and exit point to the coup. There is no description in the DPIW documents that suggests any of the dead or live chickens were examined or necropsied by pathologists or forensic professionals.

Four days later foot prints and blood were found near a sand pad and hair in the wire. One media report states blood was recovered from the barb wire itself; another written report states a blood sample was recovered from ‘wood’ on the ‘surrounds of a chicken coup at Old Beach’. The results of the hair samples have never been released.

A Canberra-based laboratory specialising in using DNA technology to diagnose the species from biological samples received two ‘wood’ samples.  The DNA sequence derived from the two ‘wood’ samples was identified as ‘fox’.

Despite attempts to obtain additional physical evidence — through the use of several sensor cameras [to obtain images of an animal returning to the coup with dead chicken carcasses], hair traps [to collect diagnostic hairs from any animal that might brush past the trap] and sand pads with fox scent attractant [to obtain diagnostic foot prints]. It appears that no additional physical evidence supporting the fox DNA has been forthcoming from this incident site.

Question: Who investigated this suspicious incident?
Answer: Officers of the Fox-free Taskforce.

Question: Did professional forensic or pathology personnel attend the scene?
Answer: Apparently not.

Question: Was there ANY time-space continuum established connecting the suspicious deaths of up to 20 chickens in the coup with any other pieces of physical evidence?
Answer: Dog, cat, devil and possibly quoll foot prints; images of devils and quolls; hair [no results released]; dog scats and wood samples identifying the presence of ‘fox’ DNA.

Question: Was there any additional supporting physical evidence linking one particular cause [e.g. animal attack] for this unusual multiple chicken death?

Question: What process of analysis took place for the authorities to confidently conclude that the detection of fox blood alone confirmed a fox attack was responsible for this unusual multiple chicken mortality?

Question:  What process of analysis took place for the authorities to conclude that the detection of the fox DNA alone was the basis for the determining that there was a live fox in the vicinity?

Question: What other explanation(s) could account for the presence of ‘fox’ DNA in samples collected at this incident site in the absence of further physical evidence linking the incident to a ‘fox’ attack?
Answer: (1) A very elusive fox (2) DNA contamination of the samples or (3)  Fabrication. 

Onus of proof

If a member of the public presented such scenario to the authorities including the presence of a fox blood specimen, one would expect that any self-respecting public authority would be not prepared to conclude on the basis of the detection of ‘fox’ DNA at the site that a live fox was the cause of the chicken deaths at that coup. One would expect that they would want to test the feasibility of the incident, the authenticity of ALL the evidence presented and surely they would require additional evidence to corroborate the conclusion that a fox was roaming free in the vicinity.

Apart from the DNA evidence assumed to be from blood — an easily transportable biological material not requiring live foxes — there has been no additional evidence collected from this incident to support the conclusion that a fox was freely roaming in the vicinity.

Question: How would an objective invasive animal risk assessor respond if the blood found at the chicken coup had been confirmed to be from a completely unexpected carnivore — like a Bengal Tiger?

Question: Would the only conclusion be that a tiger was roaming free in the vicinity?

It is accepted procedure that where there is a suggestion that an unwanted species may have entered a new ecology, the aim should always is to collect as much substantiating evidence as possible to support the initial report. Excluding all other possibilities AND the likelihood of DNA contamination or deliberate fabrication (i.e. corruption of evidence) should be a minimum standard applied.
 
The media announcement of the Old Beach incident came at the same time that the finishing touches were being made to a critical fox review document. The review’s terms of reference was to advise the State Government on the evidence about the presence foxes in Tasmania.

David Obendorf

Apart from the DNA evidence assumed to be from blood — an easily transportable biological material not requiring live foxes — there has been no additional evidence collected from this incident to support the conclusion that a fox was freely roaming in the vicinity.

Question: How would an objective invasive animal risk assessor respond if the blood found at the chicken coup had been confirmed to be from a completely unexpected carnivore — like a Bengal Tiger?

Question: Would the only conclusion be that a tiger was roaming free in the vicinity?