The trial of Saddam and seven co-defendants resumed on Wednesday after a two-day hiatus, with all men appearing in court.
The spotlight remained on Saddam's alleged signature on documents linked to the execution of 148 Shiites from the village of Dujail in the mid-1980s following a failed bid to assassinate him.
Shortly after the trial resumed, chief judge Rauf Abdel Rahman announced that "the experts verified these documents and the signatures of Saddam Hussein were found be authentic."
Abdel Rahman adjourned the trial on Monday after only an hour to allow the prosecution more time to prove that the signatures were those of Saddam and his half-brother, Barzan Ibrahim Hassan al-Tikriti.
Chief prosecutor Jaafar al-Mussawi had presented a report by three handwriting experts that he said proved those claims.
Saddam lawyer Khalil Dulaimi contested the report, demanding that a neutral body make a judgement on the authenticity of the signatures.
Khamis al-Obaidi, another defence lawyer, said the experts were interior ministry employees "and not neutral. They are against the former regime."
The documents came from the Revolutionary Command Council, the former regime's highest decision-making body.
In two earlier hearings, Saddam acknowledged that he had ordered the trial of Dujail villagers suspected of plotting to assassinate him, but stopped short of admitting he was responsible for their executions.
The prosecution has presented volumes of documents linking the former president and others to the killings, including signed letters ordering the villagers to be tried and jailed and later allegedly executed.
The deposed president has dismissed this evidence and charged that prosecution witnesses had been bribed or coerced.
The trial began in October, with Saddam and his half-brother injecting pandemonium into the proceedings with their rants and jeers against the judge and prosecutor.
The case had also been marred by the murder of two defence lawyers and the January resignation of the first chief judge, who displeased the government by not reining in Saddam's outbursts.
Since March, the case has moved into a quieter phase, avoiding the early walkouts and boycotts by defendants and their lawyers.
But international human rights experts claim that the trial continues to be conducted well below international legal standards.
After the Dujail trial, Saddam and six others will also face charges of genocide over the 1988 Anfal campaign against Kurds that left as many as 100,000 people dead.