Abdirahim abdullahi biography of martin

NAIROBI, Kenya -- Former friends of the man identified as a leader of the massacre at a Kenyan university last week tell CBS News they knew him as a "passionate" student who seemed completely happy and well adjusted.

"This is not the person we knew," University of Nairobi student Desmond Tutu Owuoth says of the man dubbed by Kenyan media, the "monster who led [al]-Shabaab mass killers."

As a three-day national mourning period draws to a close in Kenya, students at the University of Nairobi are reeling from the news that the leading suspect in last week's terror attack in the northeastern city of Garissa was one of their own -- a young man they remember well as an engaging and thoughtful undergraduate law student.

Students say the campus is collectively stunned by the news that Abdirahim Mohammed Abdullahi -- known as Abdi and by friends as Ababmo -- has been named by Kenya's Interior Ministry as the suspected orchestrator of the massacre that claimed 148 lives at Garissa