Photo: N2SA, from Aircraft Crashes Record Office.
There is very little known about this mishap right now, as of June 2014, over two years after the event. The NTSB is involved, but still have not published more than a statement of facts. The only guess we have is from non-official sources.
What follows are quotes from the sources listed below, as well as my comments in blue.
[NTSB Preliminary DCA12WA037] On February 12, 2012 at about 1120 UTC, a Gulfstream, G-IV, registration N2SA, operated by Trident Aviation of Wilmington, Delaware, crashed at Bukavu-Kamenbe Airport (BKY), Bukavu, Democratic Republic of Congo (DRC). The domestic private flight departed Kinshasa with an intermediate stop at Goma to enplane passengers and to refuel. During the landing at BKY, the airplane overran the runway, went down an embankment and came to rest in a ravine. Of the 12 persons on board, there were four fatalities, including the pilot, copilot and two passengers. The airplane was substantially damaged and there was no fire.
[Aircraft Crashes Records Office] Wrong approach configuration on part of the crew. Aircraft landed 1,200 metres after the runway threshold. Runway is 2,000 metres long.
From photos it appears the reversers are out and the flaps are down at least partially. We don't know where the 1,200 meters down the runway claim comes from. Add to all that, we don't know what caused the pilots to land long. It is obvious there is much for us to learn from this crash, but the NTSB has not been forthcoming with anything more than the statement of facts.
Aircraft Crashes Record Office, Bureau of Aircraft Accidents Archives, (B3A), Geneva, Switzerland
NTSB Preliminary Information, DCA12WA037, Gulfstream G-IV, N2SA, Bukavu, Congo, February 12, 2012