He is charged alongside Mohamed Ali Abdikar, Hassan Aden Hassan, Sahal Diriye, Osman Abdi. They have denied 162 counts of terrorism.
On Wednesday, the prosecution sought time to consult on how to proceed with the case against his alleged Kenyan accomplices
A mental examination report filed at the trail court in Nairobi stated that “he was given his last monthly injection on September 12.
“He reports abnormal experiences, he believes that people around him have evil intentions,” Dr Mucheru Wang’ombe writes in the report.
The doctor stated that the suspect requires continuous medication and repeated mental status evaluation.
“The report says that the fifth accused person be treated at Mathare Hospital every month, as such, he is not in a position to stand trial and in the circumstance we need time to consult,” prosecutor Eddie Kadebe said.
Mberesero sold second hands clothes in Garissa before his arrest following the attack on April 2 last year.
In earlier proceedings, a prosecution witness said Mberesero was seen at a mosque in Garissa where he left his traveling bag that was later collected and presented in court as an exhibit.
The suspect was arrested while hiding under a bed at the university and had initially told detectives that he was a student at the campus but later failed to give an account on how he found himself at the institution on the morning of the attack.
He is also charged with being in Kenya illegally as he had no documents allowing his to stay in the country at the time of his arrest.
The case will be mentioned on October 21.