A student survivor said that the gunmen spoke in
Swahili, and asserted that they were associated with the
Al-Shabaab group. A spokesman for the group, Sheikh Ali Mohamud Rage, said regarding the situation that "when our men arrived, they released the Muslims", but were holding Christians hostage. Rage also stated that his men's "mission is to kill those who are against the Shabab", and that "Kenya is at war with Somalia" in reference to the deployment of Kenyan troops in the
African Union Mission to Somalia (AMISOM). One suspected attacker was arrested while fleeing the area during the siege. The Kenyan government named a citizen of Somali origin Mohamed Kuno (alias Sheikh Mohamed Dulayadayn, Gamadhere, or Mohamed Mohamud) as the mastermind behind the attack, and offered a
KSh. (US$215,000) reward for his arrest. He later crossed into Somalia to join the
Union of Islamic Courts and then
Hizbul Islam, which merged with Al-Shabaab in 2010. and vowed that it would "stop at nothing to avenge the deaths of our Muslim brothers until your government ceases its oppression and until all Muslim lands are liberated from Kenyan occupation." The group also warned the Kenyan public that it would target them in their workplaces, residences, schools and universities for "condoning your government's oppressive policies by failing to speak out against them" and for "reinforcing their policies by electing them." was reportedly the son of Bulla Jamhuri chief Abdullahi Daqare in
Mandera County. The other individual was a security guard at the university; also a Kenyan citizen of Somali origin, he was thought to have facilitated entry into the institution. The last suspect, a Tanzanian named Rashid Charles Mberesero, was suspected of having been among the gunmen. He was reportedly found hiding in the ceiling and was carrying ammunition. In June 2019, four years after the attack, they were found guilty, while Sahal Diriye Hussein, also charged, was acquitted. but were later apprehended in
Kitui County in South Eastern Kenya as they attempted to cross to Somalia, three days later by Kenyan authorities following a tip-off from locals of the area. ==Reactions==