Alexandria Criminal Court acquitted Saturday six police officials charged with killing 83 protesters and injuring more than 300 during the 25 January 2011 revolution.
It is the last case of its kind in the courts.
The six suspects in the case included Alexandria's former head of the security directorate, Mohamed Ibrahim, the former head of Alexandria's Central Security Forces, Adel El-Lakany, and former chief of investigations in Alexandria's Raml district, Wael El-Komy.
The prosecution appealed the verdict.
The prosecution has accused Ibrahim and El-Lakany of inciting police and security personnel to shoot peaceful protesters with live ammunition and birdshot, as well as to terrify and disperse other protesters.
The defense has argued that the evidence provided by the prosecution is circumstantial.
Ahmed El-Hamrawy, one of the civil plaintiffs in the case, commented on the vedict, saying that video evidence showed to the judging panel was sabotaged and contained incomplete material, and claimed witnesses changed their testimonies due to bribes from the police.
The trial had been moved to Cairo's Police Academy after repeated clashes between the police and families of those killed, which led to the torching of the Alexandria Court and the recusal of the first panel of judges.