The court also handed life sentences to 50 other defendants and jail terms of between five and 10 years to 10 more.
The verdicts – which can be appealed – also saw defendants ordered to pay some $160,000 in damages for destroyed property and as compensation to the interior ministry.
The incident at the centre of the trial took place on August 14, 2013 as security forces violently dispersed two protest camps in Cairo, in an operation following the military’s ouster of Islamist president Mohamed Morsi.
The defendants then marched on Helwan police station in a southern suburb of Cairo and fired at police inside from behind barricades, killing three and wounding scores.
They were then alleged to have torched the building and 20 police vehicles parked nearby.
