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[2009] VSC 482
procedural. Evidence of the grave-digging experiment was excluded. The Crown remained able to contend, based on other circumstances, that the grave was dug the day before the killing. ([40].)
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The Crown wanted the jury to see a police experiment in which officers dug test graves, to support its argument that Chalmers could not have buried Liang within the time available the morning after her death. The fastest test took almost exactly that long. The judge found that important conditions were uncertain or different, including soil moisture, soil hardness, grave dimensions and the diggers' skills. Because those differences could change the result and mislead the jury, the experiment was excluded. The ruling did not decide whether Chalmers was guilty or stop the Crown arguing from other evidence that the grave had been dug earlier.
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2,443 words · generated 30/09/2026
In this interlocutory ruling, Osborn J considered whether the Crown could adduce evidence of a police experiment during Neil Cameron Chalmers's retrial for the murder of Shirley Liang. The central trial dispute was not whether Chalmers killed Liang. That was not disputed. The dispute was whether he killed her deliberately with murderous intent. ([1]–[3].)
The chronology gave the experiment its proposed significance. Liang was last seen alive at 8:00 pm on 24 February 2006. CCTV footage showed Chalmers carrying a body into the apartment car park at 4:48 am the following morning. He then drove to the Tallarook area. GPS data placed his car near the location where Liang's body was ultimately found for an estimated 1 hour 40 minutes. The GPS data also showed an earlier trip, on 23 February, to the vicinity of the same location. ([4]–[7].)
The Crown alleged Chalmers dug the grave on that earlier trip, and said that this supported an inference of premeditation and intentional killing. The defence account was that Chalmers, a landscaper, had gone on the first trip to look for rocks, and that the second trip followed the death, when he buried Liang in a panic. ([8]–[10].) These were competing accounts, not findings made by Osborn J.
Liang's body was found in October 2007 in a shallow grave off Ennis Road, near Tallarook. ([11].) In January 2008, three police search and rescue squad members were timed and filmed digging separate sample graves across the slope near the burial site. The fastest took 1 hour 38 minutes, the next took 2 hours 7 minutes, and the third had not finished when he was stopped. ([14]–[15].)
The Crown proposed to use those times to show that Chalmers could not have completed the burial within the estimated 1 hour 40 minutes. It also relied on the need to place lime in the grave, move the body from the road and refill the grave. ([13], [16].) The defence challenged the experiment's similarity to the actual event and warned that showing the video could invite speculation. ([17]–[18].)
Osborn J excluded the experiment. The ruling concerned admissibility only. It did not determine the murder charge, decide which account of the events was correct, or prevent the Crown from relying on other circumstances to argue that the grave had been dug earlier. ([38]–[40].)
The judge adopted the test set out in the passage approved in R v Neilan: the conditions of an experiment need not be identical to those of the event, but there must be substantial similarity. Whether the conditions are sufficiently similar depends on the experiment's purpose. A difference is especially significant where it may confuse or mislead the jury. ([21], [24].) Osborn J noted that the Court of Appeal had applied the test in R v Holmes. ([22].)
Here, the experiment was meant to support a proposition about a very short and specific timeframe: whether Chalmers could have buried Liang in 1 hour 40 minutes. The quickest test grave took 1 hour 38 minutes. The judge considered that small gap crucial. A variation of only about five per cent could make the difference between a result suggesting the task was possible and one suggesting it was impossible. In those circumstances, the experimental time could not safely support the proposed inference if there were material differences between the test and the event. ([25]–[27].)
The first major concern was the soil's condition. The experiment took place nearly two years after the burial. Although witnesses described the general soil as similar and the weather as sunny and dry at both relevant times, there was no evidence establishing the effect of different moisture conditions in the clay over that period. Evidence from the exhumation described soil becoming moist and softer at greater depth. That supported a real possibility that digging the experimental graves in 2008 was harder than digging the original grave in 2006. The judge regarded moisture as important because the clay's consistency was sensitive to it. ([29]–[30].)
The second concern was local variation. The officers dug at different points across the slope, and the officer who encountered especially hard, rock-like clay was several metres from the original grave. Notes and evidence showed that digging difficulty varied materially within a few metres. No core samples or other direct sampling had been taken to compare the soil beside the original grave with that in the experimental graves. The judge noted that the easiest test grave was also the one closest to the original grave. ([31].) This made it difficult to treat the officers' results as a reliable measure of the conditions at the burial site.
There were further differences concerning the dimensions of the grave and the identity of the digger. The measurements were made after the body was removed, and part of the hole had been enlarged to retrieve it. The judge also questioned the precision of some measurements. ([32].) There was no evidence before the court about Chalmers's actual digging capacity, but it was a reasonable hypothesis that a landscaper accustomed to digging tools might have acquired skill. The police officers were highly fit, but fitness did not necessarily answer whether Chalmers had greater efficiency using hand tools. ([33].)
Osborn J treated the dimensions and skill issues as potentially capable of clarification in evidence, if they stood alone. The soil comparability issues were more fundamental and not readily clarified. ([34].) Taken together, the uncertainties meant that no jury could properly draw the proposed inference that Chalmers could not have completed the digging and burial within the available time. ([35].)
The judge also considered the other tasks identified by the Crown. The GPS data ended on the road, but the judge observed that the device might have been turned off after Chalmers located the rough track, so the data did not necessarily establish how far he travelled on foot or by car to the site. The judge also considered that placing lime and refilling the grave would not necessarily have taken long, noting that one officer refilled his test grave in two or three minutes. ([36].) These observations did not establish what Chalmers did; they demonstrated why the experimental timings could not settle the Crown's proposed inference.
Finally, the judge considered the risk and significance of the evidence. He concluded that the experiment would encourage speculation about variables identified by both sides and had the capacity to mislead the jury. ([37]–[38].) The evidence was especially sensitive because, if the Crown's contention were accepted, it would be conclusive in itself of intent. ([39].) That combination led to exclusion.
The ruling describes the governing approach through authorities it cites, rather than announcing a wholly new test. At [21], Osborn J adopted the passage approved by the Victorian Court of Appeal in R v Neilan. That passage sets out two connected propositions: experimental conditions need not be identical, but must be substantially similar; and the permissible degree of variation is assessed in light of the experiment's purpose and its potential to confuse or mislead the jury. The passage also says that there is no precise gauge for substantial similarity and places the question within the trial judge's discretion, having regard to the surrounding circumstances. ([21].)
At [22], Osborn J records that the Court of Appeal applied the test again in R v Holmes [2008] VSCA 128. At [23], he notes that the statement of principle in R v Ireland (No 2) and its application in Thompson v R were also founded on American authority. The judgment does not set out separate, additional rules from those cases. Its express synthesis is at [24]: substantial similarity is the primary enquiry; similarity must be judged in light of the experiment's purpose; and the potential to confuse or mislead the jury must also be considered.
The application in Chalmers illustrates that this assessment is sensitive to what the experiment is meant to prove. The issue was not simply whether police officers could dig a grave in similar terrain. The Crown sought a conclusion about whether a particular person could complete a burial within a narrow time window. Because the fastest experimental time was only two minutes shorter than the estimated available time, modest differences in conditions could alter the conclusion. ([25]–[27].) The ruling therefore shows how the proposed inference and the experiment's numerical margin can make apparently small variations important.
After the ruling, the Crown could not put this particular experiment before the jury. The decision did not bar the Crown from arguing that the grave was dug the day before the killing, if other circumstances supported that contention. ([40].) The judgment does not state that the Crown's alternative argument was established, nor does it decide the ultimate question of intent.
At [21], the judgment sets out the substantial-similarity approach drawn from Neilan: “the conditions need not be identical” but “it is sufficient if there is substantial similarity of conditions.” In plain English, a test does not need to reproduce every detail exactly. But the similarities must be sufficient for the test to help the jury assess the event, rather than invite a misleading comparison.
At [24], Osborn J says the primary enquiry is whether there is substantial similarity, judged in light of the experiment's purpose. This means the court asks not only whether the test resembles the event in general, but whether it resembles the event in the respects that matter to the conclusion the party wants the jury to draw.
At [27], the judge says that “any material variation” could make the result incapable of supporting a satisfactory inference. The key feature was the narrow margin between the fastest test and the time said to be available. In ordinary terms, the experiment was too close to the threshold to withstand uncertainty about the conditions.
At [35], the judge concludes that the combined matters meant “no jury could properly draw” the proposed inference that the digging and burial could not have been completed in 1 hour 40 minutes. This was not a finding that the burial did happen within that time. It was a conclusion about what the experiment could properly establish.
At [38], the judge says the evidence did not permit a proper adverse conclusion and had the capacity to mislead the jury. That sentence captures the practical basis for exclusion: the test was not merely open to criticism about weight; its deficiencies undermined its ability to assist safely.
At [40], Osborn J makes clear that the ruling did not prevent the Crown from advancing the prior-digging contention on other circumstances. The boundary was between the argument and this particular evidentiary method. The court excluded the experiment, not the Crown's ability to make every argument about when the grave was dug.
The ruling is most directly relevant where a party seeks to introduce an experiment or reconstruction to support an inference about an event, and the experiment's probative use depends on similarity between the tested and actual conditions. It is particularly instructive where the evidence is offered to establish a narrow timing, capacity or feasibility proposition, rather than simply to illustrate a general physical possibility. ([20]–[27].)
The factors in Chalmers show what may matter in that assessment: the purpose of the experiment, the degree of similarity in physical conditions, whether conditions changed between the event and the test, local variability, the accuracy of measurements, differences between the test participants and the relevant person, and whether the proposed result is sensitive to those variations. ([24], [29]–[35].) The decision does not establish that any one factor automatically makes experimental evidence inadmissible.
The case also highlights the distinction between a difference that may go only to weight and one that undermines admissibility. Osborn J indicated that grave dimensions and the accused's capacity might have been clarified if those were the only concerns. The soil comparability issues were more fundamental in this case, especially when combined with the narrow timing margin. ([34]–[35].)
Finally, the ruling may be relevant where a jury could be tempted to resolve uncertain variables through speculation, particularly where the proposed inference would have a substantial or decisive effect on a live issue. Osborn J expressly connected the risk of misleading the jury with the high sensitivity of the evidence on intent. ([37]–[39].) The judgment does not state that high significance alone requires exclusion; it forms part of the court's assessment of this experiment.
The judgment identifies earlier authorities: R v Baker, R v Neilan, R v Holmes, R v Ireland (No 2), and Thompson v R. It characterises the test as stated in Neilan, notes its application in Holmes, and refers to the principle in Ireland and Thompson. ([20]–[24].)
The supplied judgment contains no account of later decisions applying, distinguishing, approving or rejecting Chalmers. On this source alone, later judicial treatment cannot be established. It would therefore be unsafe to state that a later court adopted this ruling as a general authority or altered its approach. The proposition that can be reported from this judgment is narrower: Osborn J applied the substantial-similarity and jury-confusion approach to exclude this particular experiment, given its purpose and evidentiary weaknesses. ([24]–[40].)
The ruling leaves the trial's ultimate factual questions unresolved. It does not determine whether Chalmers planned the killing, whether the first trip was for landscaping rocks, when the grave was dug, or what happened during the period recorded by the GPS device. Those matters remained disputed or unestablished in the ruling. ([6]–[10], [36], [40].)
The ruling also does not establish whether a different experiment, conducted closer in time or with more direct comparison of soil conditions and more reliable grave measurements, would have been admissible. The court assessed the evidence before it, including the lack of direct soil comparison and uncertainty about the original grave's dimensions. ([31]–[32].) Whether particular shortcomings can be addressed in another case would depend on that case's evidence and the purpose of the proposed test.
Nor does the decision specify a numerical threshold for substantial similarity or for when a timing margin becomes too narrow. Osborn J expressly noted that there is no precise test or gauge in the passage adopted from Neilan. ([21].) The ruling instead demonstrates a contextual assessment: the potential effect of variation was evaluated against the experiment's purpose, the evidence about actual conditions, and the risk of misleading the jury. ([24]–[39].)
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CRIMINAL PROCEEDING - Crown sought to lead evidence of experiment - Time required to dig grave - Defence objection on basis of soil similarity and dimensions of test grave, capacity to encourage speculation by the jury - Test of admissibility of evidence - Evidence does not permit drawing of proper conclusion adverse to accused - High degree of sensitivity - Evidence excluded.
1 The accused is charged with the murder of Shirley Liang at the deceased's apartment in Southbank on 24 February 2006.
2 It is not disputed that the accused killed Ms Liang but it is disputed that he did so deliberately with murderous intent.
3 Both the accused and the deceased were involved in the operation of a brothel in South Melbourne. They also lived together.
4 The deceased was last seen alive by an independent witness at 8:00 pm on 24 February 2006.
5 At 4:48 am on 25 February 2006 closed circuit video footage taken by a security camera, shows the accused carrying a body into the car park of the apartment complex in which the accused and the deceased lived. Shortly thereafter he drove his car to the Tallarook area and did not return until 10:00 am.
6 Information from the GPS device in the accused's car shows he was at a location proximate to that at which the deceased's body was ultimately found, for approximately 1 hour 40 minutes (the informant's estimate).
7 The GPS data also shows that on 23 February he had made a prior trip to the vicinity of the same location along Ennis Road, a road leading through forest. The GPS data does not establish but is consistent with the proposition that he was in the vicinity of the grave site for some hours.
8 It is the Crown case that the accused dug the grave on 23 February and not at the time he took the body for burial.
9 It follows, it is said, that the killing was pre-mediated and if this be accepted then the overwhelming inference is that it was both deliberate and intentional.
10 The defence case is that the first trip to Tallarook was undertaken by the accused, who is a landscaper, to look for rocks which he might utilise for landscaping. The second trip was undertaken with knowledge gained from the first trip, but the burial was effected, in panic, after the deceased died.
11 The deceased's body was not in fact found until October 2007. At that time an initial trial of the accused for the murder of Ms Liang had proceeded for a week in this Court, when the accused indicated that he was prepared to assist police to locate the body. Thereafter the informant and other police travelled with the accused to Ennis Road, Tallarook, and the body was located in a shallow grave down a rough track some 80 metres off the road.
12 The body had undergone some decomposition, but post-mortem findings showed that there had been a fracture of the right thyroid cornu (adjacent to the voice box) consistent with strangulation.
13 The Crown now seeks to lead evidence upon the re-trial of the accused not only of the finding and condition of the body, but of an experiment, intended to demonstrate that it is 'inherently unlikely' the accused buried the deceased in the time he had available to him at Ennis Road on the morning of 25 February 2006.
14 In January 2008, three members of the Victoria Police search and rescue squad were timed and videotaped digging separate sample graves across the slope adjacent to the position in which the deceased's body was found. The graves were of comparable dimensions to the grave site from which the body was exhumed.
15 The fastest time achieved was 1 hour 38 minutes, the next 2 hours 7 minutes and as the third officer had not completed the task by this time, he was not required to finish.
16 The Crown submits that in addition to digging the grave, it would have been necessary for the accused to place lime in it consistently with what was found when the deceased was disinterred, bring the body from the road to the grave, and fill the grave after the body was placed in it.
17 The defence objects that there is not sufficient similarity between the experiment and the hypothesis it seeks to reconstruct. It is submitted:
(1) The sub-soil conditions cannot be assumed to have been sufficiently similar two years after the event.
(2) The experiment itself showed the soil was of variable difficulty to dig. The officer who did not finish the job, was confronted with clay which was noted by the informant to be 'hard like rock' and described by the first officer to finish digging as 'almost concrete-like'. Conversely, this officer was confronted with conditions comprising layers of coarser gravel as well as hard clay soil. He agreed the conditions differed in consistency within a couple of metres and the evidence as a whole supports this conclusion.
(3) The police were required to dig holes of greater dimensions than the grave which the accused dug. The dimensions they were given were those noted on exhumation of the body. They allowed for digging under the body. The grave site excavated was 1.068 metres deep at its deepest end and 0.461 metres deep at its shallowest end. It was approximately 1.855 metres long and 1.236 metres wide (having viewed the photographs eg 57 and 61, I am also somewhat troubled as to the precision of the width and precise overall length measurements). The measurements made were recorded in part as approximate and were made after the grave site was excavated entirely and the body removed. The excavation was made primarily for the purpose of exhuming the body and identifying the manner in which it was buried, but not for the purpose of establishing with precision the dimensions of the original grave.
(4) The test graves were not dug by the accused who is a large man, who customarily carries a shovel and other tools in his motor vehicle and has experience and skill in digging because of his occupation.
18 It is further submitted by the defence that the playing of the video tape, will encourage speculation on the part of the jury and the formation of opinion on bases not properly ventilated at the trial.
19 The Crown submits that the variables relied on by the defence are all capable of fair exploration in cross-examination, and are matters for the jury to give weight to as they see fit.
20 The test which was undertaken may be characterised either as an attempt at reconstruction of the defence version of events, or as an experiment designed to demonstrate that version is not credible. (See R v Baker [1989] 3 NZR 635).
21 The test of admissibility was stated by the Court of Appeal in R v Neilan[1] by approving the following passage from American Jurisprudence 2d:
One desiring to make an experiment or test in court or to introduce evidence of an experiment or test made out of court should first show that the experiment or test is to be made or was made, as the case may be, under conditions and circumstances similar to those prevailing at the time of the occurrence involved in the controversy; otherwise, the courts will not, as a general rule, permit the making of the experiments or tests or the introduction of evidence thereof. It is clear, however, that the conditions need not be identical with those existing at the time of the occurrence, but it is sufficient if there is substantial similarity of conditions. Minor variations in the essential conditions go to the weight rather than the admissibility, of the evidence.
There is no precise test or gauge to determine when the requirement of substantial similarity has been satisfied. This depends largely upon the purpose for which such evidence is to be introduced. Speaking generally, however, the measure of permissible variation of the conditions of the experiment or test from those of the occurrence is measured by whether such variation is liable to confuse or mislead the jury. When the conditions are so dissimilar from those of the occurrence in question as to tend to confuse or mislead the jury, the evidence of an experiment or test should be rejected. The question of similarity is one that lies within the sound discretion of the trial court, to be decided in the light of all the surrounding facts and circumstances.[2]
22 That test was again applied by the Court of Appeal in R v Holmes [2008] VSCA 128.
24 The passage cited in Neilan makes clear that the primary enquiry is whether there is substantial similarity between the experiment and the thing being sought to be investigated. That similarity must be judged in the light of the purpose for which the experiment is being conducted. The judgment must also have regard to the potential of the experiment to confuse or mislead the jury.
25 In the present case the purpose for which evidence of the experiment is now sought to be adduced, is to show that the accused could not have buried the deceased's body in the 1 hour 40 minutes available to him on the morning after her death.
26 As I have said the fastest police officer took 1 hour 38 minutes to dig a 'comparable' grave at the time of the experiment. It can be seen however that no more than a 5 % deviation in this time, produces a situation in which on the one hand the accused might have buried the body within the time available and on the other hand he manifestly could not have done so.
27 In my view the results of the test are so tight, that any material variation in the circumstances hypothesised and those tested, renders the result incapable of bearing a satisfactory inference.
29 Sergeant James described the sub-soil at the time of the experiment as compacted clay containing pieces of quartzite. He said the soil in the area of the deceased's grave was generally similar to soil excavated by the three police officers. There is however no evidence as to the potential effect of a different moisture regime upon this soil two years earlier. There is evidence that both at the time of the burial and at the time of the experiment, the weather was sunny and dry. But this does not preclude the real possibility that the sub-soil clay was dryer at the date of the experiment in 2008, than it was in 2006. Senior Constable Starr, a crime scene examiner, states of the exhumation:
Upon digging to expose the remainder of the bones the soil consistency changed from dry and hard to moist and softer consistency. The soil also became darker in colour. A representative sample of soil was taken from this depth.
30 In my view this description gives rise to a real possibility in my mind that digging of the experimental graves was harder in 2008 than the digging of the grave itself in 2006. It is apparent the consistency of the soil at the grave site was sensitive to moisture content, and the evidence is that at the date of the experiment there was no sign of moisture in the clay soil.
31 The police officer who first finished the experimental dig, was the one closest to the original grave. He dug a grave pegged out some two metres across from the original gravesite. In turn the next officer attempted to dig a grave a further two metres across the slope. When he did so he encountered clay of a rock-like hardness. Both notes made at the time and the evidence of the police officers on the preliminary hearing confirm that the soil varied materially within a space of several metres in terms of difficulty of excavation. No core samples or other sampling of the clay immediately adjacent to the grave was undertaken at the time of the experiment. There is no direct comparison evidence of the soils in issue. We know they came from the same general site, but we also know they varied materially in a matter of metres in terms of hardness and that the most easily excavated experimental grave was that closest to the grave of the deceased.
32 The dimensions of the hole dug at the time of burial, were not the principal focus of enquiry at the time of exhumation. The evidence of one of the crime scene examiners is that the hole measured after the body was retrieved, was in part created by digging under the body, in order to remove it satisfactorily, together with the soil upon which it rested. As I have said the photographs also suggest that the precision of the measurement of the width and overall length of the original grave may also be open to doubt.
33 There is, as the prosecutor submitted, no evidence presently before the Court of the accused's capacity to dig. Nevertheless it is a not unreasonable hypothesis that he may as a landscaper who uses digging tools, possess skill in this regard. It seems to me that the utilisation of three police officers of a very high level of fitness, may not necessarily offset such skill. It is human experience that the use of hand tools efficiently is an acquired knack.
34 It is difficult to evaluate the cumulative effect of these matters. If the only matters raised were that of the dimensions and the capacity of the accused, then despite the obvious potential significance of these matters, I would incline to the view that these were matters capable of clarification in evidence which I should be prepared to let go to the jury. The questions relating to comparability of soil conditions are however in my view more fundamental and not readily capable of further clarification.
35 When taken together the matters I have mentioned, result in a position in which in my view no jury could properly draw the inference the accused could not have completed the digging task and in turn the burial of the deceased within 1 hour and 40 minutes.
36 The Crown case is not materially assisted by the additional tasks it hypothesises. The GPS data stops on the road at a particular time, but it may be the GPS was turned off once the rough track was located (after a U-turn) and the accused drove effectively to the gravesite. Neither the placing of lime in the shallow grave nor its filling, would have taken particularly long. Sergeant James was able to fill in the grave excavated by him in 2 or 3 minutes.
37 The Crown case would necessarily encourage speculation by the jury as to the variables, which both the Crown and the defence have identified.
38 In my view, the evidence does not permit the drawing of a proper conclusion adverse to the accused and conversely does have the capacity to mislead the jury.
39 Further, because the Crown contention, if accepted, would be conclusive in itself of the issue of intent, the evidence carries a very high degree of sensitivity.
40 In my view, the evidence should be excluded. In so ruling I do not of course shut out the Crown from contending the grave was dug the day prior to the killing. There are a series of other circumstances which taken together might support this conclusion. Nevertheless, the Crown cannot go to the jury upon the basis of the experiment which has been objected to.
[1] [1992] VicRp 5; [1992] 1 VR 57 [74] - [75].
[3] (No 2) [1971] SASR 6 at [14] - [15].
R
Chalmers
(1986) 13 FCR 165
Evidence of the grave-digging experiment was excluded. The Crown remained able to contend, based on other circumstances, that the grave was dug the day before the killing. ([40].)