The content of that testimony is under publication ban.
Magnotta is accused of murdering Concordia University student Jun Lin last year.
On Tuesday morning a Quebec court judge ruled against the defence's request to have the hearings held in camera, which would have effectively only allowed prosecutors, the judge and a court clerk to attend.
Magnotta's legal team, led by Toronto lawyer Luc Leclair, had argued barring the public from the courtroom was necessary to guarantee their client a fair trial.
But media lawyer Mark Bantey argued there's already a publication ban in effect on the preliminary hearing and the request to ban reporters and the public is highly unusual.
Magnotta has pleaded not guilty to first-degree murder in the slaying of Jun Lin last May.
The preliminary hearing will determine whether there is enough evidence to send him to trial.
Those at the courthouse yesterday included the victim's father, who travelled from China, and was accompanied by an interpreter. A lawyer representing Lin's parents said they support the media's fight to keep the hearing open.
Four weeks have been set aside for the hearing.