Local authorities assigned a security force to protect the church, but it was overwhelmed by the sheer scale of the mob.
The Coptic Orthodox Diocese of Alexandria declared the murdered priest a martyr.
Violence like this against Christians in Egypt has increased recently.
A second person, Sherif Rashad, sustained a gunshot wound and was transferred to a hospital in Alexandria.
Egyptian Coptic priest Arsanious Wadid was killed late last week. He reportedly faced years of persecution prior to his death.
Coptic Christians comprise approximately 10% of Egypt’s population, which is primarily Muslim.
Locals knew of the perpetrator as one who insulted and mistreated Christians.