Muez Hadra, a lawyer from a joint defence team, said a ninth man was acquitted. Salah referred another case to a special juvenile court.
Three other trials are continuing, including one trying Abdel Aziz el-Nur Ashr, a senior Jem commander.
Under Sudanese law, any death sentence must be ratified by both an appeals' court and the country's highest court. Then all death warrants must be signed and approved by Omar al-Bashir, the president.
Al-Bashir last week granted amnesty to 89 juveniles arrested by the Sudanese authorities following the attack, which marked the first time that decades of regional conflict had reached the capital.
Sudan set up special courts in Khartoum, Khartoum North and Omdurman, which was the target of the Jem raid, to try dozens of suspects rounded up in a security clampdown following the attack.
Defence lawyers have argued that the courts are unconstitutional and do not guarantee their clients' rights.
The cases started on June 18 when Sudan put an initial 39 suspects on trial.
The International Criminal Court (ICC) prosecutor has demanded al-Bashir's arrest for allegedly ordering his forces to annihilate three non-Arab groups in Darfur, masterminding murder, torture, pillaging and using rape to commit genocide.
Those three groups include the Masalit, Fur and Zaghawa, which is the tribe from which the majority of Jem members hail.
The UN says that up to 300,000 people have died and more than 2.2 million people have fled their homes since the conflict started in February 2003. Sudan says 10,000 people have been killed.
The war began when African ethnic minority fighters took up arms against the Arab-dominated Khartoum government and state-backed militias, fighting for resources and power in one of the most deprived regions on earth.