The German judiciary will conclude a decade-long saga on Thursday, when a Stuttgart court passes judgment on five former employees of the country's biggest gun-maker, Heckler & Koch, over the illegal sale of 4,686 G36 assault rifles to Mexico between 2006 and 2009.

Some of the rifles were almost certainly used in the murder of six Mexican students, and the probable murder of 43 others whose bodies have never been found, in the southern Mexican state of Iguala in September 2014.

Corrupt local police officers and mafia are thought to be responsible for the massacre, though human rights activists say that the responsibility should be shared: not only Heckler & Koch, but also German prosecutors, who took several years to investigate the illegal sale, and the German government, for failing to police its own export guidelines.

Jürgen Grässlin, the spokesman for Global Net – Stop The Arms Trade, who initially brought the charges in 2010, has complained about the narrow focus of the court, which did not allow any relatives of the Iguala victims to testify as co-plaintiffs, and that the scope was not broadened to include the government's possible role in the crime.

"Observations of the Heckler & Koch trial lead us to the conclusion: the export approval authorities belonged in the dock," Grässlin said in a statement. "The disregard of the victims has shaped the trial. Admitting those affected as co-plaintiffs would have made the true consequences of weapons exports to Mexico."

Demonstrators held a vigil for victims of the Iguala massacre at the beginning of the trial last May

Read more: How H&K became one of the world's deadliest gunmaker

Illegal sales

Nevertheless, Grässlin described the trial as a huge success. "Never in the history of the Federal Republic of Germany has there ever been such an illuminating criminal trial against a weapons company," he told local newspaper SWP. "Not only it became frighteningly clear that the arms export control regime in Germany is not worth the paper it is written on."

The trial turns on a loophole in Germany's arms export controls, especially tailored for Mexico: that while selling weapons to the country, in general, was allowed, German authorities wanted to ban their use in specific Mexican states: Chihuahua, Chiapas, Guerrero, and Jalisco, where war with drug cartels, corrupt police forces, and the attendant human rights abuses, were believed to be particularly prevalent.

But investigations by various journalists in the intervening years have shown that the G36 rifles were delivered to police forces in those states, and that it is questionable whether the Mexican Defense Ministry, which bought the weapons, was even aware of the restrictions laid out in end-use declarations.

Indeed, end-user certificates are normally designed to ensure that buyer countries do not sell the weapons on to other countries. But in this case, it appears the Mexican Defense Ministry was not asked for any guarantees that the weapons not be sent to the states involved. Meanwhile, H&K was simply allowed to say that the weapons were delivered to the ministry, even though it was clear this would not be their final destination.

"It was clear from the beginning where the deliveries would be sent," chief prosecutor Karlheinz Erkert said in his final statement in the trial, which took up 30 days since last May. He went on to describe the affair as "scandalous, disgraceful, and dismal."

The H&K factory in Oberndorf has sent weapons around the world

Read more: H&K ex-staff on trial over Mexican gun deal

Pushing the blame around

The five defendants are charged with violation of Germany's export laws and war weapons export control laws. But their responsibility has been mitigated by evidence that emerged during the trial that showed irregularities in how the export certificates were drawn up by government authorities who apparently misinterpreted the law.

The German Economy Ministry, in agreement with the Foreign Ministry, is in charge of these decisions, though no government official has been charged over the crimes.

The prosecution has only called for prison sentences for two of the defendants: sales department manager Ingo S. and a clerical worker Marianne B., who were implicated by an email exchange that showed the company attempting to influence the end-user agreement.

Prosecutors also recommended a one year and 10-month sentence for Peter B., a Heckler & Koch board member who went on to serve as president of a local district court. The Stuttgart prosecutor added that the sentence could be suspended if he pays a €200,000 fine.

Prosecutors also recommended that the company pay a fine of €4.1 million ($4.6 million), the approximate price of the weapons that were sold to Mexico in the deals, and acquittals for the two remaining defendants.

The defense attorneys, on the other hand, have called for their clients to be freed, arguing that they merely followed instructions based on company policy, or else were victims of the neglect of export authorities.