Investigators are focusing their attention on anti-religious groups and hate organizations, but religious leaders have been quick to say that people should not condemn individuals or groups until the investigation takes place.

They also say that every murder is a tragedy, but killing a priest in a church is a horrific sin and they believe that ultimately there will be vengeance on a spiritual level.

Father Sysoyev was famous for his missionary work in Islamic areas and also was very well known on the Internet. He was also known for the fight against sectarianism and occultism.

Investigators suspect that the murder was premeditated and had religious motives because Sysoyev had received death threats on several occasions in the past.

Right now investigators are trying to figure out what exactly happened at the St. Thomas the Apostle church that night.

On Friday hundreds of people packed the church, bringing flowers to pay their last respects and to remember the man and his work.

“It is a terrible tragedy,” Vladimir Legoyda, a spokesman for the Russian Orthodox Church, told Ria Novosti news agency.

“The murder of a priest in a church, as any other murder, is a grievous sin and a direct violation of the Ten Commandments,” he said.

On Saturday, the body of slain priest Daniil Sysoyev was brought through the crowd of mourners paying their last respects.

“Anyone could come to him and he would help anyone, especially with advice. I don’t know who would wish him dead. We were so happy that we had such a priest,” Nina Kulybina, one of the mourners, said.

Father Daniil will be laid to rest on Monday.

“He wanted to die a martyr's death. In his last book, he believed it was the best way to die. This is a happy and sad day. Sad because we lost our priest, but happy because God has fulfilled his wish and now we have someone who will pray for us in heaven. He was a very happy person and I know he is happy up there,” St. Thomas’ parishioner Yulia Evdeeva said.

Sergey Chapnin, editor-in-chief of “The Journal of the Moscow Patriarchate”, has the same opinion. He thinks the reason of the murder was the religious activities of Father Daniil. He says: “There are no other reasons behind this.”