The proceedings move into a new phase as the first witnesses take to the stand: four policemen will testify against Mubarak and his top security officials in the first witness testimony of the trial, which began Aug. 3.
Egypt's state television showed Mubarak, who is in ill health, covering his face from the sun as he was carried on a stretcher from a helicopter that landed inside the police academy where the courtroom has been set up. He was taken to an ambulance which brought him to a small waiting room.
In a step that angered many activists and relatives of those killed in the crackdown, the judge has now banned TV cameras from recording inside the courtroom, denying Egyptians a chance to follow the trial live.
Hundreds of victims' families and protesters pushed and shoved in an attempt to break through the main gates and enter the court building. Black-clad anti-riot police swung batons and briefly clashed with the protesters, who hurled stones at the security forces.
TV footage also showed metal barricades being thrown, while hundreds of anti-riot police chased young men in the streets.
Ramadan Ahmed Abu, the father of a slain protester, said he applied for permission to attend the session but that the air is charged as families of victims failed for a third time to enter the courtroom.
"People are very frustrated," he said. "We said OK when the judge decided to ban the broadcast of the trial but we want to see it ourselves," he said.
Crowds held posters showing pictures of slain protesters and shouted, "To die like them or to get their rights." One held a hangman's noose and demanded Mubarak's execution. Some set fire to pictures of Mubarak, while chanting "The people want to execute the butcher."
Nearby, about 50 Mubarak supporters cried out, "Why humiliate the president who protected us."
The 83-year-old Mubarak could get the death penalty if convicted on the charges related to the killings of protesters. About 850 protesters were killed in the uprising that forced Mubarak from power on Feb. 11, according to a government fact-finding committee.
Mubarak's sons, who face the same corruption charges as their father, are also to appear at Monday's session at the heavily fortified police academy in Cairo hosting the trial.
One of those testifying Monday will be Gen. Hussein Said, head of the communications unit of the Central Security Forces, which were deployed during the uprising to curb protests.
"This the beginning of the real trial," said Khaled Abu Bakr, a lawyer representing families of slain protesters.
Previous sessions in the trial were taken up largely by procedural matters.
Said's testimony will help untangle the circumstances in which protesters were shot dead. Prosecutors say he and the other witnesses will tell the court that top security officials ordered snipers to fire on protesters.
Attorneys have filed motions to summon more than 1,000 witnesses in the trial, including Hussein Tantawi, the head of the council of generals that took over control of the country after Mubarak's fall. Tantawi was also Mubarak's defense minister.