Habib al-Adly, Egypt's ex-interior minister, has gone on trial in Cairo for the second time.
He is accused of having ordered the shooting of demonstrators during protests that toppled the former regime.
Adly has been charged along with six former aides, the state news agency reported on Tuesday. His case has been adjourned until late May.
He is also being held responsible for insecurity that prevailed after police disappeared from the streets of Cairo in the early days of the protests.
According to an official toll, 846 people were killed and several thousand wounded during 18 days of massive nationwide street protests that forced president Hosni Mubarak to quit on February 11.
Adly was also the first member of Mubarak's regime to be put on trial in another case of embezzlement, in which he has pleaded not guilty.
The court was placed under high security, with lorry-loads of riot police and army tanks stationed outside the building.
'Trial of the revolution'
Al Jazeera's Rawya Rageh said from Cairo: "This is the trial of the revolution, the proceedings of which many hope will avenge the families of those who lost their lives or were injured during the 18-day revolt.
"The way people look at this trial is not just in terms of the fact that it carries the most serious charges into the event of the revolution, the charges of killing the protesters, which carry the death penalty.
"But also in terms of the symbolism really, this not just being seen as a trial of individuals, but also a trial of the institution, the institution of violence as it is being described here."
Around 50 people, including family members of slain protesters, staged a demonstration outside the court, shouting, "Death penalty for Adly!".
"After all, it was police brutality and their excessive use of force, that was one of the main reasons that sparked this revolution and gave momentum... to the protests during the uprising after the violence perpetrated by security forces against the protesters," our correspondent said.
The removal of Adly from office was one of the chief demands of protesters when they launched the revolution against Mubarak's regime on January 25.
Adly, along with a German businessman and Yussef Boutros-Ghali, former finance minister, is also accused of illegally profiteering from a deal to import new vehicle number plates which they allegedly bought directly without a public tender as required by law.