An unsafe conviction with flawed DNA evidence

 

Summary

In this Bermudan case, the appellant successfully appealed to the Judicial Committee of the Privy Council to have his convictions quashed because of errors in the collection, examination and interpretation of the DNA expert evidence used in the trial.

Learning points

Learning points for experts

• If you are acting in a case in Bermuda should make sure you fully understand the duties of an expert witness in Bermuda which are described below.

• Make sure you include all the relevant declarations required by the jurisdiction in which you are acting in your report.

• If you are acting in a jurisdiction with which you are unfamiliar, always make sure you understand the role and duties of expert in that jurisdiction. Never assume that the duties will be the same as they are in the jurisdictions in which you normally act.

Learning points for instructing parties:

• You should provide the experts you instruct with a written record of their duties. This is especially important if the expert does not normally act in your jurisdiction.

• If instructing an expert who normally acts in a different jurisdiction, make sure you bring to their attention any material differences between their duties in the jurisdiction where they normally act and the jurisdiction for the case.

The case

On 6 May 2014, the appellant was convicted of premeditated murder and attempted murder, using a firearm to commit an offence, and unlawfully handling ammunition. He was sentenced to life imprisonment, with a minimum term of 30 years. Apart from evidence that the appellant was a friend of a man assaulted by the victims, the prosecution’s case was entirely dependent on:

1. Expert DNA evidence provided by Ms Zuleger of Trinity DNA Solutions in Florida, and

2. Expert gunshot residue evidence about particles identified on the appellant which were said to support an inference that he had recently discharged a firearm.

On 4 May 2022, the appellant filed an application for permission to appeal on three grounds to the Judicial Committee of the Privy Council, whose panel of judges hearing a case is known as ‘the Board’. On 30 September 2022, the appellant filed a further application to rely on:

1. An additional ground of appeal relating to the DNA evidence provided by the prosecution at the trial, and

2. Fresh evidence contained in a report from a DNA expert, Dr Dan Krane.

The Board gave the appellant permission to appeal against his convictions on all grounds but one relating to possible jury bias.

In preparation for the hearing, the respondent instructed Dr Barbara Llewellyn to provide her opinion on the DNA results obtained by Ms Zuleger.

The expert evidence of Ms Zuleger

At trial, the Crown relied on the five expert reports provided by Ms Zuleger prior to the trial. Ms Zuleger also provided oral evidence. Her evidence was that she derived a partial profile from a sample obtained from four shell casings, and that the appellant could not be excluded as a possible contributor to the sample. She then estimated the likelihood of a member of the Bermudian black population (of which the appellant was a member) failing to be excluded as a possible contributor as being one in 46 million. This would mean that the likelihood that another person contributed the DNA instead of the appellant was remote.

The expert evidence of Dr Kane

Dr Krane is Professor of Biological Sciences at Wright State University in Dayton, Ohio. In his report, Dr Krane was highly critical of some significant feature of the way in which the DNA evidence was collected, examined, interpreted and presented to the jury, that were not apparent in Ms Zuleger’s evidence. Due to failures by Ms Zuleger to adhere to good practice and recent improvement in DNA analysis and statistical techniquese, he considered that the DNA evidence at the trial was flawed and inflated the likelihood that the appellant contributed to the DNA on the casings.

The expert evidence of Dr Llewellyn

In her report, Dr Llewellyn concluded that the sample of mixed DNA from the four casings should have been considered inconclusive and that no statistics should have been given on the basis of that sample because Trinity DNA Solutions did not have a protocol for creating a composite DNA profile. Dr Llewellyn also agreed with Dr Krane’s conclusion that there were significant errors in the way in which the statistical weights were attached to the failure to exclude person of interest to evidence samples at the trial. Jurors were given an unreliable statistical weight of “one in 46 million” which was inappropriately represented as equivalent to a chance of innocence.

Respondent no longer contests appeal

After considering the evidence of Dr Llewellyn, the respondent wrote to the appellant’s solicitors stating that the Crown no longer contests the appeal.

The decision of the Board

After considering the fresh evidence of Dr Kane and Dr Llewellyn, the Board decided to advise His Majesty that an order should be made:

1. Granting permission for the appellant to rely on the additional DNA ground of appeal and on the evidence of Dr Krane, and

2. Setting aside the appellant’s conviction and sentence.

The duties owned by expert witnesses in Bermuda

The Board chose to reiterate the duties of an expert witness because Ms Zuleger had:

1. Not disclosed the flaws in the DNA evidence,

2. Omitted basic assumptions from her report, and

3. Omitted factors which clearly undermined her opinion.

Ms Zuleger’s reports did not contain any declaration that she understood her duty to the court to given independent evidence or a statement that it was her duty to bring any evidence that weighed against her opinion to the attention of the court. The Board thought this may have been because of differences in the duties of an expert witness in the USA where Ms Zuleger normally acts. The Director of Public Prosecutions should also have informed Ms Zuleger of her duties as an expert witness in writing rather than verbally.

The Board noted that the duties of an expert witness in Bermuda are:

1. Expert evidence presented to the court should be and seen to be the independent product of the expert uninfluenced as to form or content by the exigencies of litigation.

2. An expert witness should provide independent assistance to the court by way of objective unbiased opinion in relation to matters within his expertise. An expert witness in the High Court should never assume the role of advocate.

3. An expert witness should state the facts or assumptions on which his opinion is based. He should not omit to consider material facts which detract from his concluded opinions.

4. An expert should make it clear when a particular question or issue falls outside his expertise.

5. If an expert's opinion is not properly researched because he considers that insufficient data is available then this must be stated with an indication that the opinion is no more than a provisional one.

6. If after exchange of reports, an expert witness changes his view on material matters, such change of view should be communicated to the other side without delay and when appropriate to the court.