An American teacher has survived a traumatic experience in Papua in which her husband was killed, and has returned here in a bid to speed up the search for justice for herself and the other victims of the shooting incident in 2002.

The calm words of Patsy Spier, however, belie any sign of frustration that she and the other victims and their families may have in that search: "Pursuing this case is in both our countries' interests," she said after meeting President Susilo Bambang Yudhoyono on Monday.

That "case" – the ambush and fatal shooting of one Indonesian and two American employees of PT Freeport Indonesia – has been one of the few remaining impediments to the full restoration of military ties between Indonesia and the United States.

Developments in this case were also the sole reason for the significant progress in improving relations between the two countries. Having convinced Congress that Indonesia was cooperating with US investigators in the search for the perpetrators, Washington restarted a training program for Indonesian Military (TNI) officers in February last year.

By November, despite lingering congressional concerns about resuming full military ties, US Secretary of State Condoleezza Rice waived the final restrictions for national security reasons – and the US is again able to supply lethal weapons to the TNI.

With relations normalized, the whole case would likely have been forgotten if not for the recent arrests – and Spier – who has not let the case drop. With the support of dozens of human rights organizations, she has lobbied Congress and the American and Indonesian presidents to raise the issue.

We support her struggle and the authorities' efforts to bring the perpetrators to justice.

And the progress so far has been encouraging: Police have arrested 12 people, including Antonius Wamang, identified as a ringleader of the killers and who police say is a member of the Free Papua Movement (OPM). Wamang had earlier been indicted by a US federal court for his role in the incident but had never been apprehended.

But there is still one lingering question – how much was the military involved – if it was at all.

The authorities have been quick to lay the blame on Wamang, who activists had previously linked to the TNI, and not the OPM. Now the police are also blaming the conflict on another at-large OPM rebel, Kelly Kwalik, who they say gave Wamang the order for the attacks.

Police say they have documentary evidence and testimony proving their case. It will be vital for these documents to be properly scrutinized in any trial to allay public reservations.

For there has never been a satisfactory answer to certain questions raised by human rights organizations in Papua. Why were security personnel in a normally tightly guarded area near the world's biggest copper and gold mine absent during the attack, which lasted at least 30 minutes. Why did some of the survivors remember the shooters wearing military uniforms?

More recent questions concern procedure: the allegations the suspects were fooled into cooperating with the authorities because they thought they would face trial in the US – instead they were handed over to authorities here – are worrying.

Many Indonesians are likely to be in favor of the unconditional lifting of the US military embargo, and there is no doubt international cooperation is vital in many areas and certainly when combating terrorism. But rushing to improve international ties by attempting to brush an incriminating incident under the carpet, in the words of one activist, would lead us instead to a "partnership of impunity."

Spier's struggle to find the truth, reminds us of another widow also looking for justice – Suciwati, the wife of murdered activist Munir. What these women have gone through reflects what it takes for an ordinary citizen to move on after their loss. Spier says that settling this case is in the interests of both countries. Citizens of all nations need to be sure that they are protected wherever they are employed; and the US government needs an assurance of cooperation, especially from the world's largest Muslim nation, in the war against terror.

For Indonesians, meanwhile, it is ultimately in our interest to know whether we are still living under the reign of those who would like to keep secrets from us. Those who kill with impunity, knowing they will never face trial.