The Athenians would have reason to change this system later by setting up more checks on what the assembly could and could not do. Athenian courts are odd to us in many ways. Greek law has in fact had relatively little influence on our own system. We can understand many of the differences if we keep in mind that the Greeks thought that the courts should be just as democratic as the rest of their government . The Athenians put together huge pools of jurors, the larger juries for the more serious crimes.
Large juries are good for at least two reasons.
The Athenians wanted to keep justice in the hands of the people, and so rejected any significant role for legal professionals. Finally, there were no professional judges . Courts have to decide at least three different sorts of issues. They were sceptical of written documents, as they worried about forgeries. Witnesses counted for a bit more, but they too could lie.