Katanga murder trial: Defense pins forensic expert, accuses him of fabricating DNA evidence

by · The Observer
Elison Karuhanga (R) the defence lawyer

On the morning of November 2, 2023, police arrived at a plot on Chwa II Lane in Mbuya, where they discovered the body of Henry Katanga lying on a small mattress in the master bedroom.

A house help was found mopping up blood. The incident was initially recorded as a murder. However, witnesses at the scene stated in their testimonies that they had heard sounds of a domestic altercation coming from the master bedroom, followed by a loud blast.

According to police investigations and prosecution evidence, Molly Katanga, the wife of the deceased, is suspected of having shot her husband and is, therefore, being charged with murder. Her two daughters, Patricia Kakwanza (28) and Martha Nkwanzi, along with the house help (George Amanyire) and the home nurse, Charles Otai, have been charged as accessories to the murder of Henry Katanga.

As the law dictates, each person is presumed innocent until proven guilty beyond a reasonable doubt. Thus, the burden of proof rests on the prosecution, which must present witnesses and evidence against the accused to the judge. The role of the defense is to show that there is reasonable doubt that the accused committed the crime they are charged with.

On September 10, 2024, the trial of Case No. 100/2024, Uganda vs. Molly Katanga and four others, resumed in Judge Isaac Muwata’s criminal court. The defense team had previously requested a court order requiring the prosecution to provide all necessary documents, which they had repeatedly asked for but had not received. These items were essential for proper cross-examination.

Molly Katanga appeared on screen, dressed in a blue kitenge, with a matching blue head wrap and a face mask. Behind her stood a bookshelf, and beside her, a police officer. The four other accused persons were present in the dock.

Seated to the judge’s right were the lead defense counsels: Peter Kabatsi, Elison Karuhanga, Macdosman Kabega, John Jet, and Zulaika Hanat. On the left side, Samaali Wakooli represented the prosecution.

As the hearing began, even before the cross-examination, the lead defense counsel informed the judge that the majority of the materials requested from the Director of Public Prosecutions (DPP) had still not been supplied. Only two had been provided, and those two were described as “terribly incompetent.” Nine essential materials had not been supplied.

The defense had specifically requested lab protocols, which were critical for cross-examining a particular witness. Other requested items included the witnesses’ work instructions, documents requisitioning evidence, data files, records of contamination in the lab, and preliminary reports supposedly forwarded to the DPP to aid in drafting the charge sheet.

“You may recall that we previously complained about having a charge sheet listing reports that are physically absent. Only one page of the 63-page quality assurance manual was supplied. Sixty-three pages of that manual were not provided,” said Kabatsi.

In addition, the 8th internal validation studies and interpretation guidelines had not been supplied; only one page of the 58-page quality assurance manual was made available.

“Nevertheless, My lord, we can proceed with the cross-examination of this witness using the materials I already have,” said Kabatsi, lead counsel for the defense.

Judge Muwata then turned to the prosecution and asked, “What can you supply?” Prosecutor Wakooli responded: “My lord, I would like to put it on record that, as the prosecution, we are obligated to disclose copies of statements made to the police, potential witness testimonies, and copies of all exhibits the prosecution intends to rely on during the trial. If you review the list provided by the defense, we have already supplied them with a copy of the report to aid in cross-examination. The witness is present in court and is available to respond to any questions that may arise.

“As for the lab protocols, they are not part of the prosecution’s evidence, nor will they be tendered in court. Therefore, it is unreasonable for the defense to request them. They are not evidence, my lord. Regarding item two, the work instructions, these pertain to a particular officer, and that officer is present in court,” she said, pointing to the witness while holding the relevant document.

“When it comes to the data files, we provided these to the defense team, and they have had the opportunity to review them for the past 10 days,” she added as the translator relayed her statement.

“My lord, we already have the final report, which is on record,” Wakooli paused briefly before continuing, “As for the quality assurance manuals, we were informed that they are confidential when we requested them.”

“In terms of disclosure, even if the prosecution intends to rely on a witness, disclosure can still be denied if providing the requested materials would prejudice security or related concerns. What is clear, my lord, is that everything the prosecution intends to rely on has been disclosed. What they are asking for is not part of the prosecution’s evidence,” she concluded, as the translator continued to convey her remarks.

Judge: “Okay, proceed.”
Kabatsi: “My lord, we have enough material for now. However, for the DPP to assert that they do not want to use a particular piece of evidence is concerning. This witness has been referring to various protocols, and we want to see what instructions were given to him and whether he followed those protocols.” (pauses) “The results depend on what he did. Those manuals and protocols are not meant to be kept secret—they exist to provide the truth. I cannot accept the statement that we can only receive evidence from the prosecution if they choose to present it. Sometimes, they have 10 witnesses but only produce five or six. Nevertheless, we are ready to proceed today.”

Lead counsel Kabatsi then handed the proceedings over to Elison Karuhanga. Karuhanga proceeded by asking the witness Andrew Mubiru to confirm several details:
• Whether he prepared a report specifically for this hearing;
• Whether all tests conducted are included in this report;
• Whether the report contains all the exhibits received;
• Whether the report documents all the tests performed on those exhibits; and
• Whether the report is conclusive, with nothing left to add or remove.

The witness confirmed each of these statements to be true. Counsel Karuhanga then presented a booklet titled DSF Confidential File Transit Ladder, containing seven documents, and asked the witness to confirm their nature. “Yes, these are electropherograms,” the witness confirmed.

Karuhanga then applied to have the documents tendered as a defense exhibit. With no objection from the prosecution, the judge approved the request.

“Now, I want to talk about a pistol,” Karuhanga said with vigor. He reminded the court that during cross-examination, the witness is required to provide yes or no answers.
Karuhanga: “Are you a trained police officer?”
Witness: “My lord, I am the director of Forensic Services for the police.”
Karuhanga: “Please answer my question— are you an officer?”
Witness: “Yes.”
Karuhanga: “Do you know how to use a pistol?”

Witness: “I have a personal firearm, my lord.”
Judge: “Gentleman, answer directly. What is the problem?”
Witness: “My lord, I’m just trying to be precise.”
Karuhanga: “So, if I were to give you a toy pistol, could you show us how to use it?”
Witness: “I’d prefer if you used someone trained in ballistics.”
(Karuhanga asked that his learned colleague be allowed to present the witness with a toy pistol, which the witness identified as a plastic imitation of a firearm.)

Karuhanga: “Is there a part called a grip?” (Witness shows the court the grip on the toy gun.)
Karuhanga: “Can you fire that pistol without holding the grip?”
Witness: “Yes, it is possible.”

Karuhanga: “How?”
Witness: “I can hold the end of the hammer.”
(The witness demonstrated to the court by holding the barrel.)
Karuhanga: “Could you kindly show us in your report where you tested the DNA on the grip?”
Witness: “We didn’t test the DNA on the grip.”

Karuhanga: “So, would I be correct in saying that there is no evidence in your report that A1 (Molly Katanga) gripped the pistol?”
Witness: “That’s not true, my lord.”
Karuhanga: “There is evidence of her on the grip?”
Witness: “There is no DNA tested on the grip.”
Karuhanga: “You know a pistol has a safety lever?”
Witness: “Yes, this imitation has one.”

As the examination continued, it became evident that the witness was well acquainted with the operation of a gun and had received training on its use.

Karuhanga: “Show us the trigger housing—the part that houses the trigger.”

(The witness showed the court the curved structure around the trigger on the toy.)

Karuhanga: “So, the trigger and the trigger housing are two parts of the gun?”
Witness: “This is the trigger, and this is the trigger housing.”

(He showed the court the two parts on the toy gun.)

Karuhanga: “So those are two separate parts?”
Witness: “Yes, My Lord, they are.”
Karuhanga: “Would you agree that you can have contact with the trigger housing without having contact with the trigger?”
Witness: “I think it is possible, my lord.”

Karuhanga: “Yes or no?”
Witness: “It is possible.”
Karuhanga: “Can you confirm, Mr. Mubiru, that you tested both the trigger housing and the trigger?”
Witness: “Yes, my lord. We swabbed both the trigger and the trigger housing.”
Karuhanga: “As one swab?”
Witness: “We swabbed the trigger and the trigger housing.”
Karuhanga: “So, you don’t have an isolated test on the trigger?”

Witness: “No, my lord, the—”

(Karuhanga interrupts him, saying “thank you,” indicating that the witness should stop there, but the witness continued.)

Witness: “The test we have is on both the trigger and the trigger housing.”
Karuhanga: “So, he doesn’t have an isolated test on the trigger.”
Witness: “My Lord, we took a swab of the trigger and the trigger housing.”
Karuhanga: “As one?”
Witness: “Yes, my lord.”
Karuhanga: “So, there is no specific test on the trigger?”
Witness: “No, because they are all part of the same area.”

(After a heated exchange, defense counsel demonstrated holding the toy gun by the trigger housing with two fingers [index and thumb], as though it were a dirty diaper).

Karuhanga: “So, if I hold the trigger housing like that, have I had any contact with the trigger?”
Witness: “my lord, that is contact.”

Karuhanga: “With the trigger?”
Witness: “It is part of the entire trigger assembly.”
Karuhanga: “With the trigger?”

(Mouthing each letter.)

Witness: “He is holding the trigger housing, but in our practice, we swab the trigger and the trigger housing together.”

Defence laywer Bruce Musinguzi holding a pistol

Counsel then referred the witness to his forensic report, specifically to page 12, paragraph 25b, 4-3, and asked him to confirm whether the police had supplied him with a specific swab of the trigger and that he was not the one who processed it.

The witness read from his report, stating that the “exhibit (swab from the trigger) was not processed because the pistol had already been examined.” He confirmed that he received a swab of the trigger but did not process it.

The witness was then asked whether A1’s (Molly Katanga) DNA was found on the grip, the safety lever, and the trigger. From his analysis, he confirmed that he did not test the grip or the safety lever, nor did he process the swab from the trigger.

Counsel Karuhanga then proceeded with a series of questions that explained the concept of DNA transfer to the court. The witness, an expert in forensic science, clarified that DNA is found in numerous cells of the human body and can be present in body fluids and skin.

It was further revealed that DNA can be transferred from one person onto an object and then picked up by another. The amount of DNA one sheds depends on the individual’s biological makeup and environmental factors such as temperature, humidity, and friction. The witness confirmed that if one person, M, touches a surface and deposits their DNA, and another person, C, touches that same surface, C would walk away with M’s DNA on their hand.

If C were to then hold the pistol’s grip, both M’s and C’s DNA could be deposited onto the pistol grip. The court was informed that only 0.07 nanograms of DNA (about the size of a needle tip) is required to perform a DNA test, and one nanogram is equivalent to ap- proximately 80 to 100 cells.

The witness also confirmed that DNA can be transferred to an object simply by speaking or sneezing near it, which is known as primary transfer. Counsel inquired further about background DNA, which would be present on an object used regularly.

“For instance, if someone touched the pistol before the incident, would it have their background DNA?” Karuhanga asked, to which the witness responded, “Yes.” Karuhanga then asked, “So, would I be correct in saying that this background DNA is irrelevant to the matter being investigated?” The witness replied, “It could be, depending on the case.”

On further questioning, the witness confirmed that DNA could appear on an object one has never touched through secondary transfer, as demonstrated in the hypothetical scenario involving M and C.

Counsel Karuhanga then directed the witness to page 21 of his forensic report, which contained the analysis of various blood samples: a swab from the bathroom door, a swab of blood from the changing room, hair with blood on the door frame, blood swabs from the western and southern walls of the bedroom, blood on the curtain to the balcony, and blood on the ceiling. All these samples were confirmed to belong to Molly Katanga.

As the witness was asked how blood could get on the ceiling in such a situation, Karuhanga argued that Molly Katanga had been subjected to severe and horrific domestic violence in that room. The expert, however, feigned ignorance, stating that he only had her DNA.

When Karuhanga asked again: “How does blood leave the body? It just comes out, right?”
Witness: (Shrugging) “You can urinate it.” (The public gallery erupted in laughter as the witness was questioned further on how a woman could urinate on the ceiling.)

Counsel Karuhanga, citing a statement made by police officer Benson Wathum, the lead investigator, on November 10, 2023, stated: “Exhibit D9 (blood on a bedsheet), brain matter on the mosquito net belonged to Katanga.”

Karuhanga argued that, based on this evidence, Henry Katanga bled only around the bed in the room. The next line of questioning focused on DNA analysis, with Karuhanga asking preliminary questions to familiarize himself with the topic in which the witness was an expert. The topic covered the DNA analysis process, specifically how to interpret results from the 25 loci (locations of the allele) and count alleles (genomes: X for female and XY for male) as shown in the forensic report tables.

Karuhanga, with the assistance of the witness, proceeded to explain how to read the tables. It was revealed that the numbers on one DNA profile should match those on the second profile in the match report, and the electropherograms should correspond with both the table and the match report.

For example, to confirm that the DNA matched Molly Katanga, Exhibit M7—a cutting from the bedsheet recovered from Molly—was compared with a swab from her mouth, which was then inserted into the match table. In one of the tables, the sample from her mouth showed two alleles, indicating that the DNA belonged to a single person and was, therefore, a single-source profile.

In contrast, if three alleles were present, it would suggest that the DNA came from at least two individuals, forming a mixed profile. With this foundation, Karuhanga referred the witness to his forensic report on page 8, where he noted the presence of three alleles (12, 15, and 16) on the bedsheet, indicating that the DNA belonged to at least two individuals.

However, the match report stated that only two alleles were found in this sample. The witness explained that the third allele had been excluded on the grounds of stutter under qualitative review. The defense argued that the match report included an allele that did not appear on the electropherogram.

The witness responded by explaining that the DNA analysis process involves both quantitative and qualitative reviews, during which data is added or removed from the tables based on the results. In response, the defense contended that the electropherograms provided by the witness were capable of being edited and argued that an analyst could potentially manipulate the data to frame someone or conceal information from the court.

On September 11, counsel Karuhanga continued his cross-examination of the witness, during which it was revealed that the witness had used specific software—EuroforMix—at a certain stage of his DNA analysis. This software, which is widely available, was an outdated version at the time the report was prepared, despite the existence of a more recent version.

Karuhanga questioned the reliability of the witness’s DNA report, given that it was based on an outdated software version. He highlighted that the software’s website included a disclaimer, stating that the use of EuroforMix was “at the user’s own risk.”

“Can I suggest to you that it was not at your own risk, but at Molly Katanga’s risk?” Karuhanga remarked. The witness dismissed these accusations, stating that the document the counsel was referencing was merely a news update about the software.

Prosecutor Wakooli objected to the line of questioning, arguing that it was inappropriate for the defense to ask the witness about the software, as he was not a software engineer. “My lord, the witness is not a software engineer, and it is a distraction for the defense to focus on the software used,” Wakooli stated.

Further examination shifted to the methods employed in the forensic laboratory to avoid contamination. The witness explained that positive and negative control tests are conducted at each stage to prevent contamination. He clarified that a negative control test is performed to check for contamination by running the machines without inserting the intended specimen—a “blank test.”

However, Karuhanga challenged the reliability of these control tests, arguing that, according to the forensic report provided by the witness, the negative control test had shown the presence of a significant amount of DNA, despite the fact that it was intended to test only air.

Karuhanga presented the court with evidence of peaks (points in the report indicating the presence of DNA), asserting that the machines used in this forensic analysis were contaminated. In response, the witness informed the court that the counsel’s statement was misleading, explaining that negative control tests do not involve “testing air.”

He clarified that the equipment used in forensic testing is sourced from the general population, meaning it may contain residual DNA from those environments. The purpose of the negative control, he stated, is to create a baseline that registers any DNA present on the equipment, allowing it to be differentiated from the DNA sample being tested.

Following this explanation, the session ended with the translator asking the judge how to translate “DNA” into Runyankore. On September 12, across High Court Room Number 3, a van from Naguru Remand Home arrived, offloading about 16 teenagers who lined up and followed an officer into the Court of Appeal.

Meanwhile, outside the High court, a crowd gathered in anticipation of the Katanga trial. Defense lawyers entered the courtroom, carrying files marked by a large number of sticky notes protruding from the sides.

Elison Karuhanga, counsel for the defense, resumed his cross-examination of Andrew Mubiru, a forensic scientist. It was revealed to the court that, according to the forensic evidence, the projectile (Exhibit 5-1) that passed through Katanga’s head had Molly Katanga’s DNA as a major contributor by a factor of a billion times.

The defense argued that this was impossible and contended that this exhibit exemplifies the challenge posed by the DNA evidence—namely, how a bullet that went through one person’s head could have another person’s DNA as the major contributor. On page 29 of the forensic report, a partial mixed DNA profile from two donors was identified on Sample 029, which was a cartridge casing recovered from the bedsheet.

The results showed that the DNA on the cartridge belonged to two untested, unrelated individuals from the Ugandan population. Citing this, Karuhanga argued that these two individuals were officers or personnel from the Uganda Police Force who contaminated the exhibits while collecting them.

Karuhanga further suggested that the wit- ness’s lab was not independent and that its methods were neither tested nor reliable. He referenced a performance report issued and published by the witness on the Directorate of Forensic Services’ website and noted that the lab had not received accreditation under ISO/IEC 17025:2017, the benchmark used to confirm or recognize the competence of laboratories.

At this point, Karuhanga handed the examination over to counsel Macdosman Kabega. During Kabega’s questioning of the witness, it was revealed to the court that the witness had been present at the crime scene supervising his team. However, his role that day excluded overseeing the officers who collected the exhibits and supervising the scene of crime officers.

The witness explained that although he was present at the crime scene, the exhibits were not collected in his presence and were instead submitted to his lab, as exhibit collection was not within his jurisdiction.

Counsel Kabega questioned the witness, asking what exactly he was supervising if the samples were collected in his absence and merely brought to him, despite his presence at the crime scene. He argued that this indicated a lack of independence in the witness’s lab.

Supporting Karuhanga’s earlier assertion that the witness manipulated the results, Kabega suggested that the witness selectively swabbed samples and fabricated a report to implicate the Katanga family. He further accused the witness of habitually shuffling samples, deliberately contaminating them, and manufacturing fake reports.

In his defense, the counsel cited the famous case of Kato Kajjubi, in which the witness, working as a government analyst at the Directorate of Government Analytical Laboratory (DGAL), testified on a DNA report.

Kabega: “Please read this to the court.”
Witness: “Andrew Mubiru is a government analyst...”
Kabega: “That is you.” (Pointing at the witness)
Witness: “I have not denied it.”
Kabega: “You are the one...”
(Kabega then pointed out that there was no mention in the report of the witness, as an analyst, collecting any tool, such as a yellow 10-liter jerrycan, questioning, “So where did you get that?”)
Judge: “Please come back to the point.”

Kabega: “Now, I am telling you, Mubiru, that this is an instance where you are cited” (pause) “to have done exactly what my learned colleague stated.”
Witness: “That is not true.”

Kabega further addressed the projectile that passed through the deceased’s head, revealing that the major DNA contributor was not the deceased but another individual who had not been hit by the projectile.

He stated that the forensic examination in the witness’s lab involved materials submitted to him by the police on Police Form 17A. The witness, in this case, served as the lead examiner, supervisor, and reviewer of all material in his lab.

Counsel for the defense then presented the witness with a copy of Police Form 17A, which listed nine exhibits. The witness confirmed the list. He was then presented with another police form received on November 3, 2023, containing the same exhibits with one additional item.

Kabega stated, “Earlier, my learned colleague asked you about tampering with exhibits. Isn’t this evidence of tampering?” He then applied to tender the form with the missing exhibit, which was only in the possession of the defense.

“This is Police Form 17A, handed to us by the prosecution during disclosure,” he added.

The prosecution objected, arguing that the rules regarding the tendering of documentary exhibits are clear. The document cannot be tendered through the witness, as he is not the author, as per sections 22 and 20 of the Evidence Act. With this, the court was adjourned until the 26th of the month, as the witnesses and the DPP had prior scheduled appointments. The witness, in particular, would be absent for two weeks.

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