A prosecution forensic officer described to the International Criminal Court (ICC) how he and a colleague enhanced speech in recordings of radio communications of the Lord’s Resistance Army (LRA) that Ugandan security agencies intercepted more than a decade ago.
Xavier Laroche told the court on Thursday that he and Sabina Zanetta only enhanced speech from cassette recordings of LRA radio communications that were intercepted by Ugandan security agencies. Laroche said they did not authenticate the cassette tapes or carry out any other investigation on the tapes.
Laroche was testifying in the trial of Dominic Ongwen, a former LRA commander who has been charged with 70 counts of war crimes and crimes against humanity. Ongwen has been charged for his alleged role in attacks on four camps for internally displaced people, sex crimes, and conscripting child soldiers. He has pleaded not guilty to all counts.
The Uganda People’s Defence Forces (UPDF) and an intelligence agency, the Internal Security Organisation (ISO), began intercepting LRA radio communications in the early 2000s. Officers who took part in intercepting the LRA radio communications testified at the ICC that commanders discussed attacks and other matters in code.
In January, an ISO officer, witness P-059, testified about his work tracking and recording LRA radio communications, which he said began in 2000. He confirmed selected excerpts of the intercepts that were played in court.
In February, a Ugandan military officer, P-003, testified about the UPDF’s interception of LRA radio communications. During his testimony in February, he also confirmed selected excerpts of the intercepts that were played in court.
On Thursday, Michael Rowse, a lawyer representing Ongwen, questioned Laroche on the details of how he and Zanetta enhanced the cassette tape recordings of LRA radio communications. Rowse also questioned Laroche regarding whether the cassette tapes may have been altered.
Laroche said he and Zanetta did not authenticate or carry out any forensic examination of the tapes.
“On this one again, I was only an operator using hardware and software to render an audio signal clearer and more intelligible. At no time did we delete or add anything on the audio signal,” said Laroche.
He said their job “was to apply filters to remove the unwanted sound and to make speech clearer.”
Laroche told the court that neither he nor Zanetta were specialists in digital audio forensics. He said the Office of the Prosecutor (OTP) brought in an expert called Alain French to develop the framework that would be used to enhance the cassette tapes using specialised equipment and a program Laroche said is called CEDAR Cambridge. Laroche said this program generated a report on each enhancement, recording technical details such as which filters were applied to which sections of the tape.
Laroche said that French enhanced a few cassette tape recordings before he, Laroche, took over. Laroche said that after that first batch, he and Zanetta took turns between other work to enhance the remaining tapes. He said they enhanced 106 cassette tapes in total.
Laroche said that when they first received the cassette tapes from the OTP’s evidence unit they photographed each tape and then they converted the tapes into a digital format.
“On this process, it was first to carry out an exhibit inventory. And for full transparency, we took pictures to show the state of the audio tapes at the time we received them,” said Laroche.
Rowse asked Laroche whether they used speech recognition software to confirm the identity of the speakers on the tapes. Laroche said neither he nor Zanetta determined who the speakers on the tapes were. He said they were only asked to enhance the audio on the cassette tapes.
Laroche also explained to the court that it was useful for him to know things like if a cassette tape had been recorded over several times or if the recording was made using a microphone held at a distance from the interception device. He said knowing these circumstances would have helped in assessing what filters to apply to enhance the speech on the tapes.
Rowse asked him whether he or Zanetta spoke Acholi, Luo, or Langi, languages that are commonly spoken in northern Uganda where the LRA operated for about two decades between 1987 and 2006. Rowse also asked whether Laroche or Zanetta spoke Arabic or Ateso, a language spoken in eastern Uganda, where the LRA operated for some time.
Laroche said he spoke a few words in Acholi, as did Zanetta. He said he also spoke some words in Arabic.
“Are you aware that Acholi has certain tonal elements to the language?” asked Rowse.
“I had no idea before you told me,” replied Laroche.
“Is it fair to say that if your treatment changed the meaning of the recordings you would not be aware of this?” asked Rowse.
“Obviously, you cannot identify if the filtering modifies the meaning of the words in enhanced state. It was quite difficult to work on enhancement when you do not know a single word of what is said,” answered Laroche.
Thursday began with the defense challenging Laroche’s testimony, arguing they had not been given enough notice of his testimony and that it would be prejudicial to their client.
Thomas Obhof, who made the submission on behalf of the defense, cited Rules 76(1), 76(3), and 77 of the ICC Rules of Procedure and Evidence. Rule 76 lays out what the prosecution is required to disclose to the defense during the pre-trial phase of a case. Rule 77 also deals with disclosures at trial.
Obhof had argued that the OTP failed to disclose that Laroche had testified about the same equipment and program in September in the ICC trial of former Ivory Coast president Laurent Gbagbo and former Ivory Coast cabinet minister Charles Blé Goudé.
Presiding Judge Bertram Schmitt and Judges Péter Kovács and Raul C. Pangalangan retreated for some minutes to deliberate on the application. When they returned, Judge Schmitt said they would allow Laroche to testify. He said they observed that Laroche’s testimony before Trial Chamber I was public and available. He also said that Laroche could be recalled if the defense felt it was necessary.
Once the judges made their decision, trial lawyer Julien Elderfield took Laroche through the procedure of identifying his August 10, 2016 statement and its annexures. Laroche acknowledged that the statement and annexures were his, and then Elderfield asked him whether he objected to the statement and annexures being used as evidence. Laroche said he did not object.
Elderfield took Laroche through this procedure because he was testifying under Rule 68(3) of the ICC Rules of Procedure and Evidence. This provision allows the statement of a witness to be entered as evidence so long as the witness does not object and is present in court to be questioned by judges and lawyers. Judges Schmitt, Kovács, and Pangalangan allowed Laroche to testify under this rule in a November 18, 2016 decision. In that decision, he is identified by witness number P-256.
Laroche is the sixth prosecution witness to testify under Rule 68. The other witnesses who have testified under this rule are Witness P-081; UPDF officer John Lubwama; Uganda’s Chieftaincy of Military Intelligence Director of Legal Services Lieutenant Colonel Timothy Nabaasa Kanyogonya; Lakoch Par Oyoo, a childhood friend of LRA leader Joseph Kony; and Witness P-352.
When Laroche concluded his testimony, Judge Schmitt said Thursday was the last day of this block of hearings. He said the court will adjourn until October 30 when Witness P-138 is scheduled to begin testifying.