Prosecutors in the former Soviet Central Asian country accuse the former president of ordering troops of special forces to open fire on people demonstrating against his policies. Almost 90 were killed and several hundred injured during the protests, which led to Bakiev's ouster.
Bakiev denies the charges. He lives in exile in Belarus.
The hearing, which began on November 17, was open to the public, held amid tight security in a makeshift court in Bishkek's Palace of Sports.
But the judge adjourned the hearings until Thursday after some victims and relatives pushed past police trying to reach the defendants, shouting, "They must be killed!"
Jyldyzbek Kulchaev, who was shot in the leg, says his two brothers were killed during the protests.
"We demand that [Prosecutor-General Kubatbek] Baibolov return to the court and give us a report [into his findings]. But I think the trial should be fair," Kulchaev says.
In addition to Bakiev, five other defendants, including his brother and eldest son, are being tried in absentia.
The 28 accused are charged with carrying out or aiding premeditated murders. They face from 10 years to life in prison. The trial is expected to last several days.
Defense lawyers had asked to postpone the trial for 40 days to better prepare for the trial. They said some of the defendants weren't acquainted with the charges against them. Prosecutors dismissed the accusations.
Chynara Janyshbaeva, who lost her brother last April, directed her anger at the defense lawyers.
"What's laughter for one person is someone else's sorrow. But for you, only money matters. Where's your conscience? I hope the spirit of those who died will curse you."
Kyrgyzstan's caretaker government is struggling to maintain stability after ethnic violence last summer between Kyrgyz and ethnic Uzbeks killed more than 400 people and prompted 400,000 people to temporarily flee.
Kyrgyzstan elected a new parliament last month in a country President Roza Otunbaeva says is creating the first parliamentary democracy in former Soviet Central Asia. But none of the five parties elected to parliament has a majority, and President Otunbaeva will be forced to dissolve the legislature if they fail to form a governing coalition and elect a prime minister.
The impoverished country hosts a U.S. airbase vital for supplying troops in Afghanistan. The U.S. Embassy in Bishkek issued a statement criticizing the violence during the trial, saying, "Kyrgyz law and international standards of human rights require that defendants be presumed innocnet."
written by Gregory Feifer, with contributions from RFE/RL's Kyrgyz Service