Police Officers Found Guilty in Acid Attack. But Doubts Remain.

JAKARTA, Indonesia — An anticorruption investigator, Novel Baswedan, was walking home from his neighborhood mosque in Jakarta three years ago when two men approached by motorbike and threw acid in his face. The attack left him blind in one eye and half-blind in the other.

On Thursday evening, a court found two police officers, Rahmat Kadir Mahulette and Ronny Bugis, guilty of carrying out the April 2017 attack. But Mr. Novel, 43, a senior investigator for Indonesia’s respected Corruption Eradication Commission, believes the attack was ordered by someone more powerful, someone he investigated — but he doesn’t know who.

Mr. Novel is widely seen by the public as a hero for his willingness to investigate leading politicians and police officials, including several who have gone to prison, in a campaign to root out the high-level corruption that has plagued Indonesia for decades.

He and his supporterscontend that the two low-ranking officers were merely lackeys or scapegoats, and that their arrest and prosecution was aimed at relieving pressure on the police to find whoever ordered the assault. Before the attack, the officers had no apparent connection to Mr. Novel or interest in the activities of the anti-corruption commission.

“The investigation of this crime should not stop with just these two defendants,” Mr. Novel’s lawyers said in a statement Wednesday before the verdict was announced. “We believe that there is a mastermind behind this crime who the police do not want to reveal.”

During the trial, Mr. Mahulette admitted in court that he had thrown the acid at Mr. Novel, and said he viewed the investigator — a former police officer — as a “traitor” because he investigated police officials. Prosecutors said Mr. Mahulette was motivated in part by Mr. Novel’s role in what by then was a four-year-old case, the conviction of Police Inspector General Djoko Susilo in an equipment procurement scandal.

Prosecutors made the case that Mr. Mahulette intended to teach Mr. Novel a lesson by splashing sulfuric acid on his body but accidentally hit him in the face.

The assertion that the acid struck Mr. Novel’s face by accident prompted widespread ridicule on social media last month.

Mr. Novel and his legal team have criticized the prosecutors, saying that they failed to present evidence found at the scene or to call three known eyewitnesses to testify.

A three-judge panel sentenced Mr. Mahulette to two years in prison and Mr. Ronny, who drove the motorbike used in the attack, to 18 months. The prosecution had sought a one-year sentence for each.

Mr. Novel’s legal team and human rights advocates called on President Joko Widodo to form an independent commission to investigate the attack.

“It was a show trial,” said Usman Hamid, Amnesty International’s executive director for Indonesia. “For Novel and many of us who have been following the case closely, the trial is seemingly designed to sway public opinion rather than to ensure justice.”

The attack on Mr. Novel caused widespread public outrage, and a lack of progress in the case was a lingering embarrassment for the police until the two officers were arrested in December.

Mr. Novel told reporters after the attack that he had investigated so many powerful people that it was hard for him to know who among them might have sought revenge.

Mr. Novel underwent repeated surgeries to repair his left eye, which turned white from the acid. The judges, in their 232-page statement of findings, said that he had lost all vision in that eye and half the vision in his right eye.

As a mitigating factor in sentencing, the judges noted that Mr. Mahulette had watered down the sulfuric acid rather than using it at full strength because he did not intend to cause severe injury.

The judges took turns reading aloud their findings, verdict and sentence, which took more than eight hours in all.

The Corruption Eradication Commission was established in 2003. It is widely credited with success and is held in higher esteem than most other institutions in the country, including the police and the judiciary, which are seen as riddled with corruption.

The president, Mr. Joko, triggered widespread protests last year when he moved to curb the agency’s autonomy by installing a supervisory board and limiting the commission’s power to wiretap suspects and hire independent staff members.

Dera Menra Sijabat reported from Jakarta and Richard C. Paddock reported from Bangkok.