IT WAS certainly a brazen attack. Soon after midnight on March 23rd eight members of Indonesia’s special forces, wearing black masks and brandishing AK-47s, forced their way into Cebongan prison in southern Java. One of them, a sergeant, Ucok Tigor Simbolon, shot four men dead in their cell. The men—all premans, or gangsters—had been detained on suspicion of having killed a soldier from Mr Ucok’s battalion during a bar fight. The soldiers, from the elite special-forces unit known as Kopassus, were exacting revenge.

This month a military court found Mr Ucok guilty of murder and sentenced him to 11 years in prison. Two accomplices were given sentences of six and eight years. All were cashiered: the judge said they had “tainted” the army’s reputation. Indonesia’s generals now hope to draw a line under a closely watched trial.

But it is not so straightforward. Kopassus is much feared. Acting as a law to itself, it was involved in the massacres of alleged communists in the 1960s, and later committed brutalities in East Timor, which Indonesia annexed in 1975, and in regions with separatist movements, notably Papua and Aceh. And so it was notable that nine other Kopassus defendants were given light sentences of up to 21 months and allowed to remain in uniform. The trials have renewed debate about the army’s role in Indonesia’s young democracy.

Though the verdicts led to protests by paramilitary types in support of Kopassus, Mr Ucok could be free in less than seven years. And that is before any appeal. Moreover, the convicted men will serve their time at military prisons, where they can expect to be treated as heroes. That is why human-rights groups deem the sentences too light.

In one crucial respect, Indonesia’s army has changed since 1998, when student-led protests overthrew Suharto, a general who seized power in 1965. Having lost seats reserved for them in parliament, the generals have since retreated from politics—or, rather, they wait until they hang up their uniforms. It is hard to imagine the armed forces seizing power again. But Marcus Mietzner of the Australian National University says this sense of a “mission accomplished” has led to complacency. Apart from its retreat from politics, the army has changed little since Suharto.

Many attributes of a modern, professional army are absent. In the event of an attack, the official doctrine is for soldiers to mobilise the civilian population to fight a “people’s war”. It is a throwback to the struggle against Dutch colonialists, but it means that soldiers are scattered in a sprawl of low-level commands. Indonesia spends less than 1% of GDP on defence and less in real terms than Singapore, with a population nearly 50 times smaller than the archipelago’s 247m. Underemployed and impoverished soldiers supplement their pay through protection and other rackets. Mr Mietzner says that peace in Aceh and elsewhere has deprived the army of income from “conflict economies”, making it reliant on “semi-criminal” activities. It does nothing for discipline.

Above all, the Cebongan killings renew concerns about military tribunals. Andreas Harsono of Human Rights Watch describes the Cebongan tribunal as a “kangaroo court”. The counsel for the defence outranked the prosecution and even the judges. Witnesses and prosecutors were intimidated. Meanwhile, commanding officers were not called to testify, suggesting that scapegoats were being made of non-commissioned officers.

Still, a shift in attitudes among army leaders seems to have taken place. An early denial by the local commander of Kopassus involvement was soon contradicted by General Pramono Edhie Wibowo, the army chief at the time. Mr Wibowo ordered an internal investigation, and said the soldiers confessed to the killings.

But perhaps Mr Wibowo was only showing political nous. He is a brother-in-law of President Susilo Bambang Yudhoyono, and now that he has retired from the army he is seeking a nomination from Mr Yudhoyono’s party to contest next year’s presidential election. The confessions have put a stop to any police probing of the army’s affairs. But it is also conceivable that the top brass realises that wayward behaviour by soldiers should not go altogether unpunished.