By Karen Allen
BBC News, Eastern DR Congo
In the hills in the east of the Democratic Republic of Congo, Singomo Mogoro is trying to come to terms with an awful reality.
Relatives of the disappeared were given some grim news
His 32-year-old sister-in-law Androsi Modestine and two nieces, aged 7 and 10, are almost certainly among the bodies discovered in a mass grave at a military base 15 km (nine miles) away from his home in Gety camp.
Their names appear on a list of civilians handed to me by the area's tribal chief.
Twenty-eight men, women and children, all of whom simply vanished whilst out searching for food between August and September this year.
There is an awful irony in the timing of their disappearances - between the first and second rounds of DR Congo's historic elections.
What makes the find all the more harrowing is that according to an eyewitness who escaped, they were abducted by the Congolese army and then killed.
"I am so angry this has happened," said Singomo Mogoro.
"There are two types of soldiers: there are some good ones trying to protect, but there are also some bad ones... who just want to destroy us."
Gety camp, where Singomo Mogoro lives, is now home to 45,000 displaced people.
Many fear the Congolese army as much as the militia, remnants of DR Congo's five-year civil war.
With the discovery of a mass grave at a remote military camp, it's not hard to see why.
Singomo Mogoro blames rogue soldiers for the killings
Human rights investigators from the United Nations peacekeeping team received news of the mass grave from two soldiers now under their protection.
At a secluded military base in Bavi, they found a cluster of shallow graves containing more than 30 bodies.
Pictures obtained by the BBC are the first published evidence of this atrocity.
According to the whistleblowers' testimonies, these people had been tortured and raped before being shot or clubbed to death by soldiers.
The obvious question asked is why this happened.
The answer investigators received? "Because they can."
It is an impunity that makes even the professionals who were the first at the scene shudder.
"They put grass on the mass grave just to hide it and when we started uncovering after 10cm we started seeing bodies and it smelt so bad," said Louis Marie Bouaka, a UN investigator.
A tragedy foretold?
A military investigation is now underway with promises that justice will be done.
Military prosecutor Major John Panza said: "We have arrested four people with the help of the Congolese army and expect there will be further arrests."
Military investigators have pledged to investigate the killings
It is understood that those in custody include senior figures from the first brigade of the Congolese army. A trial has been promised soon.
For Joseph Kabila - DR Congo's first democratically elected president - news of the graves was a blow.
Sources indicate that he wants those responsible speedily brought to book.
But a bigger challenge will be how to reform an undisciplined and fractured Congolese army.
Former militia leaders, with shady pasts, have been awarded top posts in return for their co-operation following a peace deal in 2002.
The discovery of the mass grave has given DR Congo a huge jolt. But for many in the human rights world, such an atrocity could have been foreseen.