Prosecutors have charged Alem with manslaughter. The suspect appeared before judges in a full courtroom in Alexandria on Saturday during his first trial. He has denied the allegations.
Defendant’s attorneys argued in their initial argument that the attack was not “intentional.”
The court’s top judge, Wahid Sabri, also questioned witnesses about the attack. An eyewitness said the suspect stabbed the priest “because he was a Christian” and tried to attack them if they intervened.
When the judge asked the witness to identify the suspect, he went to the defendant’s cage where the suspect was being held and identified him, according to a livestreaming on Facebook.
Prosecutors have demanded the maximum punishment for the suspect, who could face the death penalty if convicted.
Communal violence is not uncommon in Egypt. Islamic extremists have also targeted Christians in recent years, especially since the military ouster of an elected but divided Islamist president in 2013.
In September 2017, an alleged Islamic State supporter stabbed an 82-year-old Christian doctor to death in Cairo. The following year he was sentenced to death.
Egypt’s Copts, the largest Christian community in the Middle East, have repeatedly complained of discrimination. They account for about 10 percent of Egypt’s more than 103 million people.