International tribunal monitors have slammed what they call the Khmer Rouge tribunal’s lack of transparency in the wake of a heavily redacted decision to dismiss the case against former Khmer Rouge district secretary Im Chaem.

The lengthy document – many pages of it redacted – was intended to outline the rationale for why Chaem fell outside of the court’s jurisdiction, but offered little in the way of detailed reasoning beyond saying she could not be prosecuted as she was neither a “senior leader” nor one of those “most responsible” for the crimes of the regime.

That dearth of explanation, observers said yesterday, would do little to satiate the public’s thirst for justice or quell persistent claims of government interference.

Chaem’s case – along with those of Meas Muth, Yim Tith and Ao An – has been openly opposed by the government for years, with Prime Minister Hun Sen going so far as to warn civil war could break out if the cases go to trial, much to observers’ chagrin. The cases have also long been marred by disagreements between national and international investigators as to whether they should proceed.

Monday’s filing confirmed Chaem was the Preah Net Preah district secretary and that she was a “trusted and close aide” of Ta Mok, known as “the butcher”, who purged the Khmer Rouge’s own soldiers in the Northwest Zone in 1977.

It also determined there was “reliable evidence” – some of it from the former chief of the Phnom Trayoung security centre in Chaem’s district – that Chaem “had the authority to order executions”.

“There is a strong indication that she was initially considered as being one of the persons most responsible because of the alleged number of 40,000 deaths arising from the Phnom Trayoung security centre alone,” the investigating judges said in a statement.

“That was certainly an arguable contention at the time, but the evidence found during the investigation delivered far lower victim numbers on all crime sites”.

“There were about a hundred other district secretaries during the time of [Democratic Kampuchea]; the position of a district secretary was merely the third rung from the bottom in the hierarchy (above village and commune).”

Dr Craig Etcheson, a former investigator in the office of the co-prosecutors, said the investigating judges had the authority to redact whatever they saw fit from public documents. “But indeed, there is so much redacted that I am unable to form any sort of solid opinion about whether or not the reasons make sense to me,” he said via email.

“It is clear from what remains in the document that . . . investigators uncovered a great deal of additional evidence about Chaem, and that they confirmed what we in [the prosecution] believed, but could not adequately prove . . . that she operated across Sector 5, not just in Preah Net Preah District,” he added.

“They evidently were also able to establish what we deduced about the time of her arrival in the Northwest, i.e., that it was early in 1977, not mid-1978 as she has claimed.”

“That, in turn, makes it clear she was involved with the bulk of the purging of Sector 5. But it remains a mystery to me why the judges concluded that she is neither a ‘senior leader’ nor [one of those] ‘most responsible’.”

Heather Ryan, of the Open Society Justice Initiative, said the “massive redactions” made it “impossible” to evaluate and understand the decision to close Chaem’s case.

“This ‘public’ decision demonstrates a failure of the spirit of transparency essential to a publicly credible process,” Ryan said. “This is particularly problematic because of the problems of delay and allegations of political interference that have existed since the initial days of the case.”

John Ciorciari, an American legal expert who has studied the ECCC, echoed her concerns.

“There is room for debate on where to draw the line for who was ‘most responsible’ for Khmer Rouge atrocities. But to conclude that Im Chaem falls short of the bar strains credulity and demands a thorough and convincing legal explanation,” he said.

“Sadly, the key reasons for the [investigating judges’] decision seem to lurk behind the large swathes redacted, which will only fuel conjecture and doubt about why the case was dismissed.”

However, the investigating judges justified the hefty redactions, saying Chaem “continues to benefit from the presumption of innocence and the right to privacy, which restrict the contents that may be made public”.

Documentation Center of Cambodia Executive Director Youk Chhang argued the investigating judges had the intent “to justify the political influence by pointing out that [they] were unable to access the negotiations over the UN agreement that established the court”.

The investigating judges said they had sought to shed light on the intentions of the negotiators – among them the late Sok An, right-hand man to Prime Minister Hun Sen – but the UN refused access to those documents, citing confidentiality.

The investigating judges did not shy away from the “political” element of their decision; the tribunal, by design, “exercises selective justice in the objective sense of the word, because only a certain small group of people will ever be prosecuted in the courts of Cambodia for the atrocities”, they wrote.

This “was a conscious political choice during the negotiations, balancing the call for integration of the remaining Khmer Rouge into society against the desire for some form of judicial closure for the horrendous suffering of the victims”.

“It is undoubtedly difficult for the public and the victims to accept that even the soldiers who routinely killed small children by bashing their heads against trees or who had competitions about who could kill the greatest number of people, should not face justice.”

Chaem’s defence lawyers declined to comment yesterday, while international co-prosecutor Nicholas Koumjian said his team would study the decision to determine if there were legal grounds for appeal.

“We’ll be looking at both the substance of the decision and the transparency of what parts are and which are not public,” he said.