CAIRO>> Hosni Mubarak was sentenced to life in prison today for failing to stop the killing of protesters during the uprising that forced him from power last year. The ousted president and his sons were acquitted of corruption in a mixed verdict that swiftly provoked a new wave of anger on Egypt’s streets.

By dusk, thousands filled Cairo’s central Tahrir Square, the heart of last year’s uprising, in a demonstration called by revolutionary groups and the powerful Muslim Brotherhood to vent anger over the acquittals.

After the sentencing, the 84-year old Mubarak suffered a “health crisis” on a helicopter flight to a Cairo prison hospital, according to security officials who spoke on condition of anonymity because they were not authorized to speak to the media. One state media report said it was a heart attack, but that could not immediately be confirmed.

The officials said Mubarak cried in protest and resisted leaving the helicopter that took him to a prison hospital for the first time since he was detained in April 2011. They said the former leader insisted he be flown to the military hospital on the outskirts of Cairo where he was held during the trial. Mubarak finally left the chopper and moved to the Torah prison hospital more than two hours after the helicopter landed there.

Earlier, Mubarak sat stone-faced and frowning in the courtroom’s metal defendants’ cage while judge Ahmed Rifaat read out the conviction and sentence against him, showing no emotion with his eyes concealed by dark sunglasses. His sons Gamal and Alaa looked nervous but also did not react to either the conviction of their father or their own acquittals.

Rifaat opened the session with an indictment of Mubarak’s regime that expressed deep sympathy for the uprising 15 months ago.

“The people released a collective sigh of relief after a nightmare that did not, as is customary, last for a night, but for almost 30 black, black, black years — darkness that resembled a winter night,” he said.

“They did not seek a luxurious life or to sit atop the world, but asked their politicians, rulers who sat on the throne of opulence, wealth and power to give them bread and clear water to satisfy their hunger and quench their thirst and to be in a home that shelters their families and the sons of the nation far from the rotten slums,” he said. “They were chanting ‘peaceful, peaceful’ with their mouths while their stomachs were empty and their strength was failing. … They screamed … ‘rescue us and pull us from the torture of poverty and humiliation.”‘

One of the uprising’s key pro-democracy groups, April 6, rejected the verdict, saying Rifaat at once paid homage to the protesters and ignored the grief of the families of those killed by acquitting the top police commanders.

“We will continue to cleanse Egypt from corruption,” the group said.

Mubarak and his former Interior Minister Habib el-Adly, who was in charge of the police and other security forces at the time of the uprising, were convicted of failing to act to stop the killings during the opening days of the revolt, when the bulk of protesters died. El-Adly also received a life sentence.

Mubarak and his two sons were acquitted of corruption charges, along with a family friend who is on the run.

The charges related to killing protesters carried a possible death sentence that the judge chose not to impose, opting instead to send Mubarak to prison for the rest of his life.

But the case against Mubarak, his sons, ex-security chief and six of his top aides was very limited in scope, focusing only on the first few days of the uprising and one narrow corruption case.

It did not go a long way to satisfy demands of the uprising for a full accountability of wrongdoing under Mubarak’s three-decade rule when he enforced authoritarian rule with a loyal and brutal police force and a coterie of businessmen linked to the regime who amassed wealth while tens of millions lived in abject poverty.

Six top police aides on trial in the same case were acquitted, absolving the only other representatives of Mubarak’s hated security forces aside from el-Adly. It was a stark reminder that though the head has been removed — el-Adly — the body of the security forces is largely untouched. There has been no genuine reform or purge and many of the senior security officials in charge during the uprising and the Mubarak regime continue to go to work every day at their old jobs. In many ways, the old system remains in place.

The military has not shown a will for vigorously prosecuting the old regime. And that is something that neither of the two candidates in this month’s presidential runoff vote may have the political will or the muscle to change.

“Justice was not served,” said Ramadan Ahmed, whose son was killed on Jan. 28 last year. “This is a sham,” he said outside the courthouse, a lecture hall in a police academy that once bore Mubarak’s name.

U.S.-based Human Rights Watch called the verdict a “landmark conviction” but criticized the prosecution for failing to fully investigate the case.

“It sends a powerful message to Egypt’s future leaders that they are not above the law,” HRW said. “These convictions set an important precedent since just over a year ago, seeing Mubarak as a defendant in a criminal court would have been unthinkable,” said Joe Stork, the group’s spokesman.

Angered by the acquittals, lawyers for the victims’ families broke out chanting inside the courtroom as soon as Rifaat finished reading the verdict.

“The people want to cleanse the judiciary,” they chanted. Some raised banners that read: “God’s verdict is execution.”

Rifaat criticized the prosecution’s case, saying it lacked evidence and that there was nothing in what has been presented to the court that proved that the protesters were killed by the police. Because those who pulled the trigger have not been arrested, he added, he could not convict any of the top police officers of complicity in the killing of the protesters.

The question of who ordered the killings of protesters was left unanswered.

The prosecution had complained during the trial that it did not receive any help from the Interior Ministry in its preparation for the case and, in some cases, prosecutors were met with obstruction.

Maha Youssef, a legal expert from the Nadim Center in Cairo, said the judge’s verdict should be the basis of a successful appeal to throw out the convictions.

“It’s a completely politicized verdict that is meant to calm the masses. The essence of a ruling by a criminal court judge is not in the papers of the case but in his own personal conviction as someone who lives among the people and know what goes on in his society.”

Outside the courtroom on the outskirts of Cairo, there was jubilation initially when the conviction was announced, with one man falling to his knees and prostrating himself in prayer on the pavement and others dancing, pumping fists in the air and shooting off fireworks.

But that scene soon descended into tensions and scuffles, as thousands of riot police in helmets and shields held the restive, mostly anti-Mubarak crowd back behind a cordon protecting the court.

Protests also erupted in the Mediterranean city of Alexandria on Egypt’s northern coast. They chanted slogans denouncing the trial as “theatrical” and against the ruling generals who took over for Mubarak, led by his former defense minister. “Execute them, execute them!” chanted the protesters in Alexandria. Similar protests broke out in the city of Suez, which was a hotbed of the uprising, and other cities.

Mubarak and his sons — one-time heir apparent Gamal and wealthy businessman Alaa — were acquitted on corruption charges, with the judge citing a 10-year statute of limitations that had lapsed since the alleged crimes were committed.

Just days before the verdict was made public, the state prosecutor leveled new charges of insider trading against the two sons. It now appears that these charges may have been an attempt to head off new public outrage once the acquittals of the Mubarak sons were made public.

The sons have been serving time in Torah prison in Cairo, the same prison where Mubarak was flown after the sentencing. Mubarak’s wife Suzanne is reported to be living in Cairo.

It has appeared all along that prosecutions since Mubarak’s fall targeting relatively few high level officials and their cronies have been motivated largely by a desire to appease public anger expressed in massive street protests that continued long after Mubarak’s ouster.

Scores of policemen charged with killing protesters have either been acquitted or received light sentences, angering relatives of the victims and the pro-democracy youth groups behind the uprising.

There is no officially sanctioned process of truth and reconciliation under way to account for the entirety of the regime’s abuses because the military rulers would never sanction such an inquiry.

And taking on corruption in Egypt is difficult, due largely to the entrenched power of the military which by some analysts’ accounts controls 20-40 percent of the economy.

Still Egypt today is greatly changed since Mubarak’s rule. There have been democratic elections for both parliament and president. And the hard-won freedoms of speech, assembly and protest are defended vigorously by the public.

Thousands of riot police and policemen riding horses had cordoned off the complex where the court is located to prevent protesters and relatives of those slain during the uprising from getting too close. Hundreds stood outside, waving Egyptian flags and chanting slogans demanding “retribution.” Some spread Mubarak’s picture on the asphalt and walked over it.

Mubarak’s verdict came just days after presidential elections have been boiled down to a June 16-17 contest between Mubarak’s last prime minister, one-time protege Ahmed Shafiq, and Mohammed Morsi of the Muslim Brotherhood, a fundamentalist Islamist group that Mubarak persecuted for most of his years in power.

In a statement posted on his Facebook page, Shafiq said he could not comment on court rulings, but added that the Mubarak trial has shown that no one was above the law in today’s Egypt and that no one could recreate the old regime.

The acquittal of the six police officers, he added, did not mean that he approved of their “tactics.”

In contrast, a spokesman for Morsi said the verdicts were “shocking” and vowed retribution.

“The blood of our martyrs will not go in vain. We will work as Egyptians for the sake of a just retribution and the retrial of those who committed crimes against this nation,” said the spokesman, Ahmed Abdel-Atti.