The board of inquiry formed to probe what really happened during the attack on the Kenya Defence Forces (KDF) camp in El Adde, has started its work amid claims of betrayal.
Preliminary findings showed the local clan might have played a role in the attack's planning and execution. The Marehan clan lives in the El Adde, Gedo region where the camp was.
It emerged three soldiers who had escaped the massacre and hidden in a village elder's house were hunted down by Al Shabaab and lynched, together with the host, after being allegedly betrayed by the villagers.
"The Marehan clan feels KDF has been working to help the Ogaden and other clans seen as their rivals and that is what we think drove some of them to betrayal," said a source who asked not to be named.
The soldiers had apparently ran for almost five kilometres after removing their military uniform before ending up at the elder's home where they were shielded for a while.
The militants attacked the military base at dawn on January 15 killing more than 100 soldiers, stole military ware and held other KDF soldiers hostage. Sources said the attack might have been planned for days and there was no way it could occur without the local clan's knowledge.
The attackers used vehicle borne improvised devices, an indication they had planned the raid for a long time and exploited a tactical weakness during rotation of forces to carry out the raid.
The team visited the camp on Thursday as part of their inquiry and is expected to brief the Chief of Defence Forces Samson Mwathethe on their findings this week in accordance with standard military practice. The team is expected to give answers on critical questions on how the attack happened and lessons learned.
The military is still mum on the official figure of the dead soldiers, missing and those injured.
The team of investigators is to focus on the question of the local clan's role, if there was negligence, the number of dead, missing, injured, if the equipment was working well, if the command structure in place was working and if there was prior intelligence warning of an attack.
Gen Mwathethe has denied claims KDF had prior intelligence on the raid. A commander with the Somali National Army said they warned KDF of a pending attack by the terror group.
"A number of soldiers are missing in action. We have not accounted for all of them. We will know more once the team investigating the attack completes its work," said Mwathethe.
The team is to also explain the role of the African Union Mission in Somalia (Amisom) in the attack and aftermath.
"Amisom did not have the necessary capacity and capability to assist our troops in El Adde. We were, therefore, compelled to act and mobilise our own resources to respond to the situation," he said.
The team is also expected to determine when the families will be compensated as per the military's rules.
Amisom's role is set to be the next focus. "It is now time for Kenya to review its move to join Amisom and instead operate on its own as it was in the beginning," chairman of Parliament's Foreign Relations and Defence committee, Ndungu Githinji, told BBC.
Amisom was formed in 2007. KDF went into Somalia in October 2011 and became part of Amisom in February 2012.
Mwathethe said KDF has since liberated 120 towns from Al Shabaab.
El Adde was the third Amisom forward operating base that Al Shabaab has overrun in the last seven months.
Al Shabaab is split into two with one gang supporting ISIS and the other Al Qaeda. It is believed that the ISIS faction carried out the El Adde attack.