The family of Boston marathon bombing suspect Dzhokhar Tsarnaev is keeping a low profile as he goes on trial Monday for the dramatic attack in which three people died.
Despite giving an emotional press conference just after the bombing in April 2013, Tsarnaev's parents who live in Russia have remained silent since.
Dzhokhar, now 21, faces the death penalty if convicted of planting the two pressure cooker bombs near the finishing line of the race that killed three and injured 264.
His father Anzor Tsarnaev has not answered his mobile phone and did not respond to requests for comment passed through acquaintances.
His parents had moved from the US back to Russia and were living in Makhachkala, the main city in the Dagestan region of the North Caucasus when the attacks took place.
There is no evidence that either parent has gone to the United States over the past year, and they have apparently moved out of their former home to live separately elsewhere.
In April of last year, Dzhokhar's mother Zubeidat Tsarnaeva accused the US security services of needlessly killing her eldest son Tamerlan while trying to capture him.
Both parents have stressed their sons' innocence and lamented ever going to the United States.
Ethnic Chechens, the family originally hails from Kyrgyzstan in Central Asia, where the brothers spent most of their youth. They moved to the US in 2002.
Though of Chechen origin, they never actually lived in Chechnya, where the regional leader Ramzan Kadyrov has gone to extremes to stamp out an Islamist insurgency, particularly after a daring rebel raid on downtown Grozny last month.
Last year Kadyrov said the brothers got what they deserved, even calling them "devils".
Reached on Monday, Kadyrov spokesman Alvi Karimov told AFP he had no comment on Dzhokhar Tsarnaev's trial. "He never lived in Chechnya, he was not born here," he said.