Evidentiary Proof Standards: The Genealogical Proof Standard (GPS) -v- the Forensic Investigative Proof Standard.

      The way in which a forensic/law enforcement investigator goes about approaching an investigation into a crime really isn’t that dissimilar to the way a genealogist goes about approaching an investigation into establishing facts relevant to family history. Both seek to establish, as closely as possible, and with the aim of being beyond any reasonable doubt, the facts in relation to a matter under investigation, with both being achieved through the gathering and analysis of the available evidence.

     From the outset, investigators, both forensic and genealogical, need to ask two initial questions, which form the basis for the relevant investigation. These questions are:

1. What is it that I am seeking to prove, and,
2. What evidence do I need to gather to prove it?[1]

    The type of evidence that is gathered, which needs to be exhaustive, and how it is analysed, will determine the level of certainty that can be had in relation to the ultimate findings of the investigator.[2] From this respect, it needs to be established that there are generally two levels (degrees) of proof standard:

1. proof based on the balance of probabilities (preponderance of the evidence), and
2. proof beyond a reasonable doubt.[3]

     In a criminal (forensic) investigation, and with reference to the prosecution proving their case, the proof standard is always ‘proof beyond a reasonable doubt’, which, although very subjective in nature, suggests that any doubt present needs to be reasonable, and not fanciful possibilities.[4] It should be noted here that the standard is ‘beyond REASONABLE doubt’, and not ‘beyond ALL doubt’. The ‘beyond reasonable doubt’ proof standard allows for the fact that the actual truth of a matter may never truly be known, although it can be known with a high degree of certainty based on the evidence presented, and the way in which this evidence is analysed and correlated.[5] This higher level of proof standard differs from ‘proof based on the balance of probabilities’ in that the proof standard of ‘balance of probabilities’, while not treated as a mathematical standard, necessarily is a

“…reasonable attempt to find the facts in the circumstances of a particular case…[and that the facts were]…more probable than not.”[6]

      While not to be treated as a ‘mathematical standard’, the proof standard of ‘balance of probability’ is routinely used to justify an investigative finding, based on the amount of evidence that exists both for and against a question being asked. For example, in an historical situation where an investigator is attempting to establish if A is the child of B, evidence is gathered and an analysis is carried out. The result of that evidence gathering is one piece of evidence that suggests that A is in fact the child of B, whereas three pieces of evidence that have been gathered suggest that A is the child of C. As a result of this, the investigator, based incorrectly on the proof standard of ‘balance of probability’, and using that standard as a ‘mathematical standard’, arrives at the conclusion that A is the child of C as there is more evidence than not that suggests that this is the case. From a genealogical perspective, and extrapolating from this example, this can result in inaccuracies in family trees, and incorrect relationships identified between members of that family tree.  

     The proof-standard of ‘beyond reasonable doubt’ seeks to reduce the amount of uncertainty that can arise from evidence gathering and analysis by subjecting the evidence items that have been gathered to a number of specific tests. These tests concern initially, whether the evidence is both relevant and reliable.[7] The ‘reliability’ test is broken down into further tests that concern hearsay, opinion, tendency and coincidence, and credibility of specific items of evidence and witnesses associated with those evidence items, amongst others.[8] Once individual items of evidence are tested, the evidence itself can then be assessed against other evidence.

     The Board for Certification of Genealogists (US) has created a proof standard specifically for genealogists, which it has designated the Genealogical Proof Standard (GPS).[9] This proof standard contains five interdependent components that genealogical investigators need to work through to ensure a high degree of certainty that the results of their investigation that have been arrived at are representative of the facts of an event. Those five interdependent components are:

1. Reasonably exhaustive research – emphasizing original records providing participants’ information – for all evidence that might answer a genealogist’s question about an identity, relationship, event, or situation.
2. Complete, accurate citations to the source or sources of each information item contributing – directly, indirectly, or negatively – to answers about that identity, relationship, event or situation.
3. Tests – through processes of analysis and correlation – of all sources, information items, and evidence contributing to an answer to a genealogical question or problem.
4. Resolution of conflicts among evidence items pertaining to the proposed answer.
5. A soundly reasoned, coherently written conclusion based on the strongest evidence available.[10]

     As can be seen from the five components listed above, the GPS is very similar in its approach to evidence analysis as the forensic investigative approach of ‘proof beyond reasonable doubt’, as opposed to the proof standard of ‘balance of probability’. Adopting either the GPS approach, or the forensic investigative (‘beyond reasonable doubt’) proof-standard approach, will ensure that any investigative findings are closer to representing the truth of a matter than not. These two approaches, rather than initially being concerned about the evidence as a whole, tends, initially, to be more concerned with the relevance and reliability of specific items of evidence, with the evidence considered in its entirety only after those tests have been completed.  

     It should be noted that relevance and reliability of evidence may change as further evidence of a matter comes to light. It is important to be open to all evidence, even negative evidence that may contradict a particular theory the investigator may hold about how an event unfolded. As long as the theory fits the available, tested, evidence, and all evidence available is considered, then there can be no criticism of the findings that are ultimately made, even if over time those findings adapt and change to new evidence as it appears and is tested to the relevant GPS or forensic investigative proof standard.   

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Endnotes:

[1]     Andrew Palmer, Proof: How to Analyse Evidence in Preparation for Trial, 2^nd edn, Sydney, Thomson Reuters, 2010, p. 1. Palmer specifically relates his analyses of evidence to preparation for trial, whereas I have somewhat adapted his wording so as to be equally applicable to genealogical investigations. Both initially adopt the same theoretical approach to evidence analysis though.

[2]     The gathering of evidence needs to be exhaustive to be able to make accurate findings, but exhaustive does not mean that ALL evidence needs to be located prior to a finding being made, as this would not be achievable. As new evidence comes to light, the investigator necessarily adapts the theory of the investigation to cater for that new evidence.

[3]     Bryan A Garner (ed), Black’s Law Dictionary, 10^th edn, United States of America, Thomson Reuters, 2014, p. 1624.

[4]     Stephen Odgers, Uniform Evidence Law, 13^th edn, Sydney, Thomson Reuters, 2018, pp. 1326-1328. See also R v Dookheea (2017) 91 ALJR 960; [2017] HCA 36, and Green v The Queen (1971) 126 CLR 28.

[5]    Evidence analyses at the higher-level proof standard of ‘beyond reasonable doubt’ will be the subject of future posts on this website.

[6]     Stephen Odgers, Uniform Evidence Law, p. 1316.

[7]     Ibid. p. 310.

[8]     Ibid. Any specific legislation and tests cited all relate to Australian-based legislation, although the basis of this post is general in nature, so as to be applicable in other jurisdictions.

[9]     Board for Certification of Genealogists, Genealogy Standards, Washington, Turner Publishing Company, 2014, p. xiii-xiv.

[10]   Ibid. pp. 1-2.