The DNA Evidence
10 DNA tests were conducted by Mr Robert Goetz, the officer in charge of the Forensic Biology Laboratory in the Division of Analytical Laboratories of the Institute of Clinical Pathology and Medical Research. He prepared two reports dated 19 October 1998 and 16 November 1998. He gave evidence at the trial, first on a voir dire and, after his Honour determined that the evidence was admissible, he gave evidence before the jury.
11 In his first report, Mr Goetz said that DNA testing had been carried out on blood from the victim and from the foetus on the one hand, and each of the Appellant and the other two employees, Keith Phillips and Ian Burrell, on the other hand. The report was a three-page document of which the third page was an annexure indicating the results of the tests in tabular form. The first two pages was the written report which, relevantly, contained the following passage:
"The results show that Keith PHILLIPS or Ian BURRELL cannot be the father of the foetus.
The results show that Juan GALLI could be the biological father of the foetus. Statistical analysis of the results shows the following:
Paternity Index 172:1
Relative Chance of Paternity 99.4%
Relative Chance of Non-Paternity 0.6%".
12 It is significant to note that only the table outlining the results of the tests was tendered before the jury. The report quoted above was not tendered before the jury. Mr Goetz, however, gave oral evidence before the jury explaining the results in the table to the effect which I will outline below.
13 The second report by Mr Goetz provided further information of comparison between the samples from the victim and foetus with the blood of the Appellant. The results were set out in a table. The report to which the table was annexed concluded:
"The results show that Juan GALLI could be the biological father of the foetus. Statistical analysis of the results shows the following:
Paternity Index = 14330:1
Relative Chance of Paternity = greater than 99.99%
Relative Chance of Non-Paternity = less than 0.01%
When these results are combined with those in my previous report (dated 19.10.98) the statistics are as follows:
Paternity Index = 2,400,000:1
Relative Chance of Paternity = greater than 99.9999%
Relative Chance of Non-Paternity = less than 0.00001%."
14 As with the previous report, it was only the table that went to the jury, not the report. However, the reports were used by the police in a record of interview that was before the jury.
15 The Appellant consented to two recorded records of interview, the first on 9 June 1998 and the second on 25 November 1998. He made no admissions and maintained his innocence. During the course of the second ERISP the two reports from Mr Goetz - that were not tendered - were put to him in terms and he was asked to comment on them. This ERISP was played at the trial to the jury immediately before the closing of the Crown case.
16 The following questions by the police and the Appellant's answers appear in the transcript of the video which was supplied to the Court:
"Q30 Yes, just where it says, The results show.
A And ah, the second one, the second line?
Q31 Yeah.
A The results show that Keith Phillips or Ian Burrell cannot be the father of the foetus.
Q32 And can you just read the - - -
A The results show that Juan Galli could be the biological father of the foetus ….. sorry my reading, analysis of the results show the following.
Q33 And can you tell me what those results show?
A Which one, that from the top - - -
Q34 Yeah.
A - - - or I don't understand what …..
Q35 ….. I'll just tell you on this third page. This is showing that you could be the biological father - - -
A Ah hmm.
Q35 - - - of the foetus, and this is the statistics that show it. It says, The paternity index is a hundred and seventy two to one, which means you could be - - -
A Mmm.
Q35 - - - if there's a hundred and seventy two people, then you could be one of those.
A Mmm.
Q36 And the relative chance of paternity is ninety nine point four per cent and the relative chance of non-paternity is nought point six per cent.
A ….. I don't understand those numbers anyway.
Q37 O.K. I'll just show you - - -
DETECTIVE SENIOR CONSTABLE HUNT
Q38 Should I explain those, what those statistics mean.
PLAINCLOTHES SENIOR CONSTABLE GILL
Q39 Well it's saying, you understand that it shows that Keith Phillips and Ian Burrell cannot be the father.
A Well, it say so very clear in there, yes.
Q40 And that there's a chance that you can be the father.
A Yeah, mmm.
Q41 And it's saying that ninety nine point four per cent, that's - - -
A That I, that I could be the father.
Q41 - - - how much of a chance that you are the father.
A - - - that I could be the father of that child.
Q42 Yes, of Hannah's child.
DETECTIVE SENIOR CONSTABLE HUNT
Q43 What do you say about that?
A Well, as I say before I've got nothing to do with it. I got nothing, nothing to do with it.
PLAINCLOTHES SENIOR CONSTABLE GILL
Q44 Sorry, and that as dated the 19th of the 10th,1998. There was some further tests done on your sample of blood alone.
A Ah hmm.
Q45 And this is the second test results. I'll just read it for you. I says the results show that Juan Galli could be the biological father of the foetus. Statistical analysis of the results show the following: The paternity index says that in fourteen thousand three hundred and thirty people, that you could be one of those. So the results have gone up higher.
A Mmm.
Q46 So there's an even bigger chance now that you are the father. Do you understand that.
A (NO AUDIBLE REPLY)
Q47 It's also saying the relative chance of paternity is greater than ninety nine point ninety nine percent. So there's less than nought point nought one per cent that you aren't the father. It also goes on to show the paternity index, sorry, then they were done again - - -
A Yeah.
Q48 - - - these are combined with these ones over here. That you were the only one in two million, four hundred thousand - - -
A Ah hmm.
Q49 - - - that you could be the father. And it shows that ninety nine point nine nine nine per cent of chance that you are the paternal father.
DETECTIVE SENIOR CONSTABLE HUNT
Q50 [It] says, Greater than.
PLAINCLOTHES SENIOR CONSTABLE GILL
Q51 And there is less than nought point nought nought nought one per cent that you aren't the father. What can you, have you got anything to say about these results?
A ….. there's got to be something wrong. I haven't, as I said, I haven't done anything to her, nothing at all, I've been, as I said, I, I've been with them for over six, six years with her.
Q52 And - - -
A Never dream of or thought of doing anything to her.
…
PLAINCLOTHES SENIOR CONSTABLE GILL
Q69 Is there anything else you wish to say about this matter, Carlos?
A Well, I would say it again and over and over again, I got nothing to do with her pregnancy. I'm not that kind of person to, or take advantage of anyone. So that's all I got, I got to say. I've got nothing to do with her pregnancy. What, and the tests, what the tests are shown it look like I, I am the one, but I say there's got to be something wrong in there. I haven't done anything to her.
Q70 So you see there's no other reason for the results showing that you are the father. Can you think of any reason?
A Well, it's got to be something wrong in there."
17 This video containing these questions and answers was played to the jury immediately before the closing of the Crown case.
18 As I have indicated above, Mr Goetz gave evidence on a voir dire. It is not necessary to set out the whole of the evidence given. It is sufficient to note that in some respects Mr Goetz made observations during the course of the voir dire which he did not repeat before the jury.
19 When the Crown Prosecutor tendered the table annexed to the second report, it was tendered even on the voir dire as a one-page document, without the covering report. However, in the course of the voir dire the following evidence was given:
"Q It is the combination of these two lots of results referring to your paternity index that you then establish the probability of 99.9999 per cent, is that right?
A That's correct.
HIS HONOUR: That's not shown here though, is it?
CROWN PROSECUTOR: No your Honour, I haven't tendered that in the documentation."
20 Subsequently, in the course of cross-examination on the voir dire the following occurred:
"Q So what it comes down to at the end of the day is you are saying in terms of the probabilities the real question that you are answering is what is the chance of taking somebody from the population at large and having them match this particular combination of alleles?
A That's correct.
Q That's not the same thing as saying that it's 99.9999 per cent certain that Mr Galli is the father, is it?
A No, that's not what I'm saying, I am saying the relative chance of paternity is 99.999 per cent, I am not saying that he is 99.999 per cent likely to be the father.
HIS HONOUR: What does the relative chance of paternity mean though?
A It's just another way of re-wording the probability of paternity, the paternity index. If I had a paternity index of 100 to 1 that would be a relative chance of paternity of 99 per cent. It's just another way of rewording it, it really flows very much from the Family Law Act which specifies the way they want the reporting done and that is the way they want the reporting done in that case.
Q This isn't a Family Law Court, this is a criminal court and the Crown has an obligation if it is to prove the case against this accused of proving it beyond reasonable doubt. Can you equate that in any way to this probability of paternity test.
A No I prefer actually to use the paternity index, the 100 to 1 or 1000 to 1 or 2.4 million to 1 rather than the relative chance of paternity. I think that can sometimes be a bit misleading."
21 The reference to the relative chance of paternity and the figure of 99.9999 per cent during the course of the voir dire was not repeated in the evidence given by Mr Goetz before the jury. This may have been because of Mr Goetz's opinion that it could be misleading.
22 In his evidence before the jury Mr Goetz said:
"… the quality of the DNA was very good. As a forensic biologist we're used to dealing with samples that are extremely degraded, samples that have been outside in the sun for weeks if not months, samples that are minute, samples the size of pinheads. In this case the blood samples, I had a number of mls of blood and with the foetus I had a sample that was of extremely good quality. There was no problem getting the DNA in sufficient quantities from all the samples I analysed."
23 Mr Goetz gave evidence to the jury about the nature of DNA and the conduct of tests for DNA. He gave evidence about testing for paternity by identifying the DNA of the mother and of the foetus, which could then identify what the foetus would have inherited from the father.
24 The two tables of results, being the annexures to Mr Goetz's reports of 19 October and 16 November 1998, were identified and tendered. As noted above, the covering reports were not tendered.
25 Mr Goetz referred to the first table of results of DNA testing, being the table attached to his report of 19 October 1998. He told he jury:
"From my testing I could exclude Keith Phillips and Ian Burrell from paternity so they could not be the father of the foetus, however, I was unable to exclude Juan Galli from paternity."
26 Mr Goetz referred to the second table, being that annexed to his report of 16 November 1998 as containing the results of further DNA testing of samples of the blood from the victim, the foetus and the Appellant.
27 Mr Goetz explained to the jury that the columns of the tables comprised different DNA markers. He noted the presence of particular alleles in the foetus which were not present in the blood sample from the mother. They must have come from the father. He explained that the absence of such alleles in the case of both Mr Phillips and Mr Burrell enabled him to exclude them as possible fathers. The presence of the alleles in the case of the Appellant enabled him to state that the Appellant could be the biological father.
28 With respect to each DNA marker referred to in each column of the tables, the last line item in each column was a computation of a "Paternity Index". Mr Goetz explained this to the jury as follows:
"Paternity Index is a calculation that is made where I have not been able to exclude someone. If I can't exclude him, exclude the possible father I need to know the significance of the inclusions. What is the probability that Mr Galli could be the biological father as compared to anybody else taken at random in the population. And to do that I take two hypothesis (sic) to calculate my paternity index. My first hypothesis is what is the likelihood that Juan Galli is the biological father and my second hypothesis is what is the likelihood that Juan Galli is not the biological father but someone else taken at random in the population is."
29 Mr Goetz then explained the significance of the figures in the table with respect to the issue of whether the Appellant was the father. He indicated that the paternity index for each DNA marker was based on the combination of the probability that he would have passed on the relevant allele to the foetus and the frequency of the occurrence of that particular allele in the general population, based on a specific database.
30 He also gave the following evidence:
"Q As a combination of each of those paternity indexes for each particular DNA marker, at that point in time did you come to a combined total paternity index at that stage?
A Yes I did.
Q What was the result of that combined paternity index?
A The combined paternity index is calculated by multiplying those numbers at the bottom together, the bottom of that column, bottom of that table together. If you multiply all those numbers together and you come up with a combined paternity index of 172 to 1. So using the 10 different DNA markers in that table, it's 172 times more likely that Juan Galli is the father of the foetus than anybody else taken at random from the population."
31 Mr Goetz went on to explain the further testing that he had done to generate he second table, with the application of the Profiler Plus system. He said that he had looked at each marker for both the foetus and the mother and then by deduction identified what was passed on to the foetus by its biological father. He testified that in each of nine DNA markers, the Appellant possessed the allele which was inherited by the foetus from its father. Mr Goetz calculated the paternity index for each of these markers. He then gave the following evidence to the jury:
"Q In regard to this further testing, did you come to a further refined paternity index?
A Using the profiler plus system, the combined paternity index was 14,330 to 1.
HIS HONOUR: Q What does that mean?
A Using profiler plus alone Mr Galli is 14,330 times more likely to be the father of the foetus than anybody else taken at random in the population.
CROWN PROSECUTOR: Q So the results of the first tests were, you told us, a 172 times more likely Mr Galli was the father of the foetus than a person taken at random from the population.
A That's correct.
Q In regard to the second test the figure is Mr Galli was 14,330 times more likely to be the father than a person taken at random from the general population?
A That's correct.
Q Because these are different DNA markers and different indicators are you able to then combine those results?
A Yes I am.
Q Once you combine those results from a total of 18 DNA markers … what was your result there?
A The combined paternity index now is 2.4 million to 1 which means that Mr Galli is 2.4 million times more likely to be the biological father of the foetus than anybody else taken at random in the population."