The Volgograd train station bomb that killed at least 17 people on Sunday was set off by a Russian man from the nearby region of Mary El who had converted to Islam and joined Dagestani militants, officials said.
The suspect, identified as Pavel Pechyonkin, worked as a paramedic with an ambulance service but left home in 2011 and joined Dagestani militants after converting to Islam and changing his name to Ansar Ar-rusi.
In response to his parents' video appeals for him to come home, Pechyonkin posted his own video online this spring, saying he was following God's will and would not turn back.
"I have come here only to make Allah pleased with me, to earn heaven," he said in the video.
In a plea by his parents recorded in March, his father, Nikolai, admonished his son to "drop those weapons" before he would become a "terrorist."
"Do all Muslims go around with weapons?" the father said in the video. "You are the only one so stubborn. What harm have people done you? […] You are going to kill children."
His mother, Fanaziya, said that she was also a Muslim, and pleaded with her son that he should abstain from using violence.
"What kind of the Koran…" she said, apparently too pained to finish the sentence, before finding the strength to continue: "I don't believe that Allah has ever said that one must kill people."
"Pasha, I'm appealing to you — please come back," she said. "Imagine, what is happening to me now, how I am feeling. …I'm not living, I'm in hell."
"Imagine that somebody were to kill your parents, how would that make you feel? Why are you turning children into orphans?" she said.
For the video recorded message from Pavel's parents, click here.
In his response, Pechyonkin told his parents that initially their "tears had saddened" him, but that he had then decided he would not be swayed.
"I didn't want to watch your appeal, I thought that it would weaken me, that it would make me softer," he said, adding that he had "no intention" of turning back.
"Why should we follow those Christian commandments, when Allah, may he be glorified, urges us to fight those kafirs [unbelievers]," he said. "Why shouldn't we leave their children orphaned?"
He also brushed off his mother words that the Koran does not instruct believers to kill.
"I am not inventing anything from the Koran, I am reading," he said.
"You say that a man has no right to kill," he said. "Those kafirs have occupied radio and television, and they are making the kind of religion that they need for the Muslims. They are trying to convince you that a man can't do this."
A video recorded by Pavel Pechyonkin as a response to his parent's plea to come home. ( YouTube / VDrezerv)
After their initial video appeal in March, Peshyonkin's parents followed their son to Dagestan in September, to search for him and record another videotape with a plea for his return. That second appeal found no response, a law-enforcement official said.
"He's our son, no matter what he's like, he's still our son," his mother said in the September video. "Pavlik, I am appealing to you — please come back, we are ready for anything, just come back."
"Law enforcement bodies have told us that there's no blood on your hands [...] They will hold you for two, maybe five, hours, and you will go home together with us," his mother said.
The identity of the suicide bomber could be confirmed through DNA analysis using a blood sample from the elder Pechyonkin, the official said.