In a 550-page closing brief submitted to the Khmer Rouge tribunal’s Trial Chamber, the defence team for Khieu Samphan, former Khmer Rouge head of state, articulated its arguments for acquittal on all charges, including genocide, enslavement and extermination.

Submitted this month and obtained yesterday, the document argues that discriminatory policies against groups such as the Vietnamese and predominantly Muslim Cham ethnic minorities did not exist, and concludes with the long-standing contention by the defence that Samphan’s innocence hinges on his supposed lack of criminal intent. “There was never a racist ideology in the policy he has believed in,” Samphan defender Anta Guisse noted in an email.

For crime sites such as the Trapeang Thma dam, where tens of thousands are estimated to have perished, the defence does not refute the fact that a large number of deaths occurred, but argues that evidence of medical attention proves there was no intention of “extermination”.

“The fact that [measures of care] existed demonstrates that the personnel of the [Trapeang Thma dam] bore no intention of killing the workers by the imposition of living conditions calculated to cause their death,” reads the argument, which is also applied to other crime sites. Evidence presented at trial suggests that outbreaks of diseases such as cholera and chickenpox decimated workers, and those requesting medical aid were punished.

Samphan’s defence argues that the radical socialist agrarian revolution the Khmer Rouge attempted “was not about working for the benefit of a small few but about rebuilding the foundation of a new society where everybody could benefit from collective labour”.

Khieu Samphan, former Khmer Rouge head of state, attends a hearing in Case 002/02 at the Extraordinary Chambers in the Courts of Cambodia in 2015. Peter Ford/ECCC

Repeating a common refrain throughout the trial, the document states that rather than the fault of senior leaders it was the “incompetence of many [other] responsible commanders and cadres that perverted a political project”.

Samphan and co-defendant Nuon Chea were already sentenced to life imprisonment in the first phase of trial. The prosecution is seeking another life sentence in Case 002/02.

The defence’s case rests in part on its rejection of Samphan’s liability through “joint criminal enterprise”, by which one is responsible for the actions of a group committing crimes under a common purpose. “Considering the important legal arguments we have raised . . . We are indeed insisting that if we had an objective and impartial tribunal, Khieu Samphan could not be found guilty through joint criminal enterprise,” Guisse said.

In its 800-page closing brief, the prosecution argued that Samphan’s rank, his closeness with Pol Pot and co-defendant Chea, and his position in the office responsible for monitoring policy implementation confirmed his responsibility in the crimes.

The prosecution also highlights testimony suggesting that specific instructions were handed down from “the upper echelon” to exterminate the Cham minority, which was corroborated by survivor accounts. Similarly, testimony from Khmer Rouge cadre Prak Sok pointed to a policy to target Vietnamese as “the responsibility of each battalion that received exact instructions”.

Long-time court observer Panhavuth Long said he was “not surprised” by any of the defence’s positions. He encouraged the court to take note of the defence’s criticism to ensure it demonstrates that it is operating “in a way that is credible, open and transparent”.

Guisse, meanwhile expressed doubt that the court would fully take into account the arguments.

“We are not under the illusion that our arguments on the responsibility of our client are going to be heard.”