The Independent Uganda: You get the Truth we Pay the Price
Cross Examination of DNA Forensic Expert
SPECIAL REPORT | ANTHONY NATIF | As recorded in court, in the case Uganda Vs Molly Katanga and adapted from @TonyNatif on X.
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Yesterday, the state started cross-examining Mrs Katanga’s third expert witness, DW4. As we previously reported, she’s a British DNA forensics expert with a resume longer than the Thames.
In her 30 years in the field, she helped start the DNA forensics program in Great Britain and trains a number of police forces in the UK, to wit: Metropolitan Police (Scotland Yard), City of London Police, Kent Police, British Transport Police, Sussex Police, Hampshire police and the Military Police. She’s done similar work in New Zealand and Oman, trained the Turkish army and teaches as an honorary lecturer at University College, London.
In her evidence-in-chief, she told Justice Rosette Kania that the state’s DNA report before her was meaningless and worthless in as far as it sought to answer the question of who touched or fired the gun.
She advised the court that only fingerprints found on the trigger could answer that.
She questioned the process, methods and conclusions the state drew from their DNA analysis and said due to gross contamination in the collection of exhibits and in the laboratory, the results before court are unreliable. But even if they were, they couldn’t show which of Mr or Mrs Katanga actually touched or fired that gun.
The state has argued that the presence of Mrs Katanga’s DNA on the gun showed she participated in the killing of her husband.
DW4 essentially handed the prosecution a scientific mountain to climb. They asked for an adjournment to prepare. She flew back home.
Yesterday, she was back in the witness stand for what was at times a tense encounter with Assistant DPP Samali Wakooli.
At other times, it had the feel of a knowing subject matter expert gently educating a prosecutor who must have spent a week on a forensics crash course.
It showed at times.
DW4 reminded Wakooli that all she did was a desk review, and she didn’t need ISO certification for that. She pushed back on claims that she was biased or that her report went beyond her scope of expertise.
Wakooli told DW4 that her report was merely a critique of PW8 (Mr Andrew Mubiru)’s report and she didn’t interact with the exhibits and didn’t run independent tests.
DW4: “as is standard practice”.
SW: were you informed that the analyst holds a superior qualification from the UK? (Note: Mr Mubiru holds A Forensic Science Master’s Degree from the UK. DW4 holds a Bachelor’s Degree, is one of the pioneers in the field and teaches as an Honorary Lecturer in one of the best forensic science programs in the UK)
She looked puzzled at the question and then calmly answered: ‘It bears no relevance to my review.’
SW:Â Your firm is not ISO (17025) certified
DW4: Correct. We don’t run laboratories
SW: Are you aware that the analyst is an ISO 17025 assessor?
DW4:Â In which area? Assessors are specific to an area. Is it biology, chemistry?
SW: Are you aware?
DW4: I’m aware (from listening to his testimony) but I’m unaware as to the specific field
SW: Do you as an individual hold ISO certification?
DW4: You can’t hold it as an individual….
They then got into the hierarchy of forensic DNA propositions:
1-Source level activity answers the “who”
2-Activity Level-“how”?
3-Offense Level-“when”?
SW: Offense level is a preserve of the court.
DW4: Correct, science cannot resolve that
SW: In your review of PE6 (DNA report) does it cover activity or offense level?
DW4: No. DNA report doesn’t cover either
SW: Confirm whether a person fired is offense level
DW4: No, it’s activity because offense would be who murdered….
The prosecution didn’t take too nicely to some of her extensive answers, preferring “yes or no and we move on” answers. She reminded them that some of the questions they were asking weren’t suited for yes or no answers.
Wakooli asked her to “stop blabbering”. The defense took umbrage at that. The judge intervened. The judge preached calm. DW4 stared straight at the Assistant DPP, cool as you like.
UgandaVsMollyKatanga
Cross Examination of DNA Forensic Expert
Yesterday, the state started cross examining Mrs Katanga’s third expert witness, DW4.
As we previously reported, she’s a British DNA forensics expert with a resume longer than the Thames.
In her 30 years in the… https://t.co/aiOGm5adA1 pic.twitter.com/0gujVXo9xi
— Anthony Natif (@TonyNatif) July 15, 2026
