Mohamed Ahmed Hassanein, also known as Hamam el-Kamouny, was sentenced to death by an Egyptian state security court on Sunday for his part in the 2010 killing of Coptic Christians.
Two other defendants accused of aiding Hassanein in the killings are due to be sentenced on February 20.
The sentence comes amid widespread anger among Copts who feel that the government is not doing enough to protect them.
Much of the resentment centers on the lengthy process in bringing the accused to trial. For a year, court proceedings against the three Muslim men were postponed numerous times. The U.S. Commission on International Religious Freedom denounced the delays to the trial and to convicting the men.
One year ago, as Coptic Christians prepared to observe Christmas Day, gunmen traveling in a car opened fire in a shopping district in the town of Nagaa Hammadi and later in front of the southern Egyptian town's main church as worshippers emerged from midnight mass. The Jan. 6 shooting resulted in the deaths of six Christians and one Muslim security guard, who was assigned to protect the church.
Early this month, just as Copts were ringing in the New Year, an explosion outside the Coptic Christian church in Alexandria took the lives of 23 people. It is suspected that a suicide bomber was behind the attack. The bombing was condemned by world leaders, including President Barack Obama.
Also, most recently, a 71-year-old Christian man was shot dead last week and his wife and four others were injured after an off-duty policeman opened fire on a train bound for Cairo.
The shooting occurred just hours after Egypt recalled its envoy to the Vatican and accused Pope Benedict XVI of "meddling" in its internal affairs after he called on Egypt, Iraq and Nigeria to do more to allow Christians to practice their faith safely.
The government insisted that the latest gunman's motive was not sectarian and blamed it instead on his mental instability.
The attacks have threatened to destabilize the historically peaceful relations between Egypt's majority Muslim population and the minority Christians.
Responding to last Tuesday's train shooting, Christian Solidarity Worldwide called upon Egypt to implement more measures to stem sectarian violence and "tackle the extremism at its heart."
Christians make up around eight to 12 percent of Egypt's population.