Bahaji was born to a Moroccan father and a German mother. The family moved to Morocco when Bahaji was nine years old. Bahaji came to Hamburg in 1995. He enrolled in the electrical engineering program at the technical university in 1996. Bahaji lived in a student home during the weekdays and he spent weekends with his aunt, Barbara Arens. Both of them loved computers, and he called her his "high-tech aunt". She saw that he was secular until other students introduced him to radical Islam. She later put an end to the weekend visits.
Bahaji told his employer in June 2001 that he was going to an internship for a software company in Pakistan. His aunt, Barbara Arens, says that she was suspicious and that she went to the police and pleaded to them "to do something." She says that police took no action against Bahaji.
Bahaji and cohort Ramzi Binalshibh were charged with 5,000 counts of murder by German officials. Binalshibh has since been arrested, but Bahaji is still at large. Bahaji is accused of being in charge of the logistics of the Hamburg cell.