Army Staff Sgt. Logan J. Melgar, a Green Beret whose death is being investigated by the Navy Criminal Investigative Service. (Photo: U.S. Army)

More than a year has passed since the death of U.S. Green Beret Logan Melgar in Bamako, Mali. Investigators now believe they have men of interest – two Navy SEALS and two Marine Raiders. The four face charges that include felony murder in the strangulation death of Staff Sgt. Melgar.

A preliminary hearing on the charges is scheduled for Dec. 4.

The alleged authors of the heinous crime were suspected of skimming from a fund for informants and taking prostitutes back to the safe house in Bamako, as reported by the Daily Beast. Picking up some duct tape, the four suspects broke down his door around 5 a.m., bound him with tape and put him in a chokehold till he lost consciousness and died.

Melgar, a Lubbock, Texas native with Special Forces training, had completed two deployments to Afghanistan as an engineer sergeant.

Melgar’s death was more than a tragic ending to a noble life of service – it brought to light a U.N. mission intended for peacekeeping but eventually taking sides in Mali’s insurgent war.

The U.N. mission – MINUSMA – had been escalating peacekeeping duties to active operations and finally to “proactive and robust” intervention – language that seemed to encourage more offensive operations.

Eventually 15,436 personnel were based in Mali from over a dozen countries. Burkina Faso was a top troop contributor. Senegal contributed the most police.

“We need to be able to hit the terrorists before they hit us,” explained the U.N.’s top official in the northern city of Gao.

But the U.N.’s dilemma goes beyond its lack of preparation or anti-terrorism equipment. Diplomats are instead debating: Should U.N. forces engage in counterterrorism at all?

A front-line role violates the core principle of impartiality and ultimately makes peacekeepers less safe, critics say.

“Peacekeepers are only meant to use deadly force to protect civilians or to stop spoilers from threatening a peace process, not to pursue any group’s military defeat,” said Aditi Gorur, head of Protecting Civilians in Conflict at the Stimson Center, a research center based in DC.

A more aggressive counterterrorism mandate, she and others argue, could hurt the U.N.’s ability to mediate between warring groups.

Already, the International Committee of the Red Cross has described the U.N. as a “party to the conflict.”

The Mali mission is considered the most dangerous UN mission in the world; 22 peacekeepers were killed this year alone and 177 have been killed since the mission began in 2013. This week, Canada announced it will end its Mali mission after it expires in July. U.S. plans are not known.