Military Auditor: TNI BAIS Member's Method of Mixing Caustic Liquid is Creative

The Military Auditor II-07 Jakarta stated that the act by members of the Strategic Intelligence Agency (BAIS) TNI Detachment Headquarters in mixing rust remover liquid with battery acid to attack KontraS activist Andrie Yunus was a creative method.

This assessment was conveyed by the Auditor during the continuation of the trial at the Military Court II-08 Jakarta on Wednesday (13/5). The agenda of today’s trial was for the defendants to provide mutual testimonies.

In this trial, it was mentioned that the background of the acid splashing against Andrie was based on the annoyance and emotions of the defendants.

Andrie was considered to have trampled on the TNI institution because he interrupted a closed DPR meeting with the TNI at the Fairmont Hotel discussing the TNI Bill revision, which was ongoing in March 2025.

Defendant I, Sergeant Two Edi Sudarko, initially wanted to punch Andrie over that interruption action. However, Defendant II, First Lieutenant Budhi Hariyanto Widhi, suggested that Andrie should just be splashed to make it quicker and more practical.

“Did Defendant I know that the liquid consisted of rust remover and battery acid?” asked the Auditor.

“I didn’t know,” answered Budhi.

“So, only Defendant II knew about the mixture? Did Defendants III and IV know?” continued the Auditor.

“No,” he said.

“Defendant II mixed the rust remover liquid with used battery acid; where did that idea come from?” asked the Auditor.

“There was no idea at the beginning, it was just spontaneous,” admitted Budhi.

“What did Defendant II want from the splashing result to Andrie Yunus?” interjected the Auditor.

“Nothing,” answered Budhi.

The Auditor was not satisfied with that answer.

“Well, it must be like this, Defendant. The idea from Defendant I to punch, that would definitely result in bruises, swelling, or bleeding, scratches. That was rejected by Defendant II, ‘don’t, don’t punch. Just splash him.’ Well, just splashing turned out to be Defendant’s idea, which I would say is very creative. Not just rust remover, but also mixing it with battery acid, which, in quotes, if Defendant II listened to witness 5 yesterday, battery acid has fatal consequences if it gets on… if it gets on fabric, the fabric will be destroyed but not immediately. Maybe in a few days it will be destroyed. Well, that. So, where did the idea to mix it come from?” asked the Auditor again.

“There was no idea. So, the first time I entered that workshop, what I saw was battery acid. I opened the battery, I poured it into the tumbler,” said Budhi.

“Didn’t you think, wow, this is dangerous? Did that thought cross your mind?” interjected the Auditor.

“Yes, it didn’t,” said Budhi.

There are four soldiers from the BAIS TNI Denma who are being prosecuted in the acid splashing case against KontraS External Division Deputy Coordinator Andrie Yunus.

They are Defendant I Sergeant Two Edi Sudarko, Defendant II First Lieutenant Budhi Hariyanto Widhi, Defendant III Captain Nandala Dwi Prasetyo, and Defendant IV First Lieutenant Sami Lakka.

Based on the indictment letter, the reason the defendants splashed Andrie with acid was because they were annoyed with Andrie’s behaviour, who often voiced issues of militarism.

This included Andrie’s actions along with a civil society coalition interrupting the closed meeting between the DPR and TNI regarding the discussion of the TNI Bill at the Fairmont Hotel in March 2025.

“With that incident, the defendants considered brother Andrie Yunus to have insulted the TNI institution, even trampling on the TNI institution,” said the auditor when reading the indictment letter in the previous trial.

The defendants are charged with violating Article 469 paragraph 1 subsidiary Article 468 paragraph 1 further subsidiary Article 467 paragraph 1 in conjunction with paragraph 2 in conjunction with Article 20 letter C of Law Number 1 of 2023 concerning the Criminal Code.