The attack killed 25 people, mainly women. President Abdel-Fattah el-Sissi on Monday identified the bomber as 22-year-old Mahmoud Shafiq Mohammed Mustafa.
The video is a recording of CCTV footage from outside a chapel adjacent to St. Mark's Cathedral, seat of Egypt's ancient Coptic Orthodox Church. It shows a dark figure crossing the street and walking through the gates of the church. Moments later, the blast sends clouds of dust and debris through the windows.
It was among the deadliest attacks in recent memory to target Egypt's Coptic minority, which makes up around 10 percent of the population.
Small protests were held outside the church in the aftermath of the attack, as Christians accused the government of failing to protect them, a complaint that goes back many years.
Officials and government supporters have touted the quick identification of the suspected bomber as proof of the efficiency of the security bodies, but Christian activist Nader Shokry said more could have been done to prevent the attack.
"How did all this planning take place without the security knowing about it?" he said. "You are saying that this person belongs to a terror group and has been previously arrested... So you should have kept a close eye on him."
Three men and a woman were arrested in connection with Sunday's attack and other suspects were on the run, el-Sissi said.
