The court set a verdict session for July 22, after referring its recommendation to the country's top religious authority, the Grand Mufti, for a non-binding legally-required opinion.
Public Prosecutor Hisham Barakat was killed in a car bomb attack on his convoy in Cairo, an operation for which Egypt blamed the Muslim Brotherhood and Gaza- based Hamas militants, though both groups have denied it.
The Interior Ministry released a video last year showing clips of several young men confessing and admitting going to Gaza for training from Hamas, though some of them later denied the accusations in court.
Egypt faces an Islamist insurgency led by Islamic State in North Sinai, where hundreds of soldiers and police have been killed.
The group has also increasingly carried out attacks in Egypt targeting Christians in a spate of church bombings and shootings that have killed some 100 since December.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
Barakat was the highest-ranking state official to die in a militant attack since President Abdel Fattah al-Sisi, a former military chief, ousted President Mohamed Mursi, a Brotherhood leader, in 2013 after mass protests against his rule.
