In the fortnight since Kym Owens was attacked in Maynooth, gardaí have interviewed 200 people.
The first-year student, who is 18, remains under sedation in hospital after suffering multiple injuries in an assault on her way back to college on Sunday November 18.
The timeline of what exactly happened remains unclear as foggy conditions prevented a clear view of the scene on CCTV footage.
Gardaí hope that when Ms Owens regains consciousness, she may be able to shed light on the attack and give them clues to help in their investigation.
Ms Owens left her home in Castleblaney, Co Monaghan, and boarded the A2B bus at around 6.15pm, arriving in Maynooth two hours later.
She walked 1km to Moyglare Abbey Estate, where she was attacked sometime between 8.15pm and 8.40pm.
“She was within 500m of her digs when she was seriously assaulted and left unconscious on the footpath,” said Supt Gerry Wall, from Leixlip Garda Station.
He said Ms Owens, a first-year student of arts at Maynooth University, suffered “extensive head injuries”.
Supt Wall said the bus started its journey at Monaghan, stopping at Carrickmacross and Castleblaney and going on to Ardee and Slane, before reaching Maynooth.
He appealed to anyone on that bus, who got on or off and who got off at Maynooth to contact gardaí.
He said it was “very, very possible” the attacker was on the bus, but stressed it was not the only avenue they were exploring.