As the parents of the Boston Marathon bombing suspects insisted their sons were “set up," one uncle told reporters that his nephews have brought shame to the family.

The suspects, 26-year-old Tamerlan Tsarnaev and his 19-year-old brother Dzhokhar A. Tsarnaev, are accused of placing two bombs near the marathon finish line on Monday, killing three people and injuring more than 180.

They also allegedly killed a security guard at the Massachusetts Institute of Technology Thursday night before engaging in a shootout with police in the suburbs of Boston.

Tamerlan Tsarnaev was killed in the standoff with police. Dzhokhar was captured Friday evening after a standoff with police.

Their mother, Zubeidat Tsarnaeva, told CNN Friday that her sons were “set up” and suggested that the authorities had been trailing Tamerlan.

“He never told me that he was on the side of Jihad,” she said in a phone interview from Russia.

“How could this happen?”

Their father, Anzor Tsarnaev, called Dzhokhar “a true angel” in phone interview with The Associated Press.

"Dzhokhar is a second-year medical student in the U.S. He is such an intelligent boy. We expected him to come on holidays here,” he said, speaking from the city of Makhachkala in the Russian province of Dagestan.

Later in the day, he told ABC News he spoke to his sons after the bombings.

"We talked about the bombing. I was worried about them.”

He said his sons reassured him, saying: "Everything is good, Daddy. Everything is very good."

He added: "If they kill my second child, I will know that it is an inside job, a hit job. The police are to blame. Someone, some organization is out to get them."

But one uncle said the brothers, ethnic Chechens who have lived in the U.S. for about a decade, have brought shame to the family and all Chechens.

Ruslan Tsarni, who lives in Montgomery Village, Md.,urged his surviving nephew to turn himself in.

“He put a shame on our family, on the Tsarnaev family,” Tsarni told reporters outside his home. “He put a shame on the entire Chechen ethnicity, because everyone now is playing with the word ‘Chechen.’ So they put that shame on the entire ethnicity,” he responded.

Tsarni said his brother Anzor, the boys’ father, recently returned to Russia. He said he had not been in touch with Dzhokhar and Tamerlan for quite some time, but said something must have happened to them.

“Somebody radicalized them -- but it’s not my brother who just moved back to Russia, who spent his life bringing bread to the table, fixing cars... He didn’t have time for anything else,” Tsarni said.

When asked what he thought might have motivated the attacks that his nephews are accused of carrying out, Tsarni suggested it was not about ideology.

“The only thing I see as being behind this is: being losers,” he said. “Not being able to settle and thereby hating everyone who did.”

He also offered his condolences to the families of those killed and injured in Monday’s attack at the marathon.

“For those who suffered, we are sharing with them in their grief,” he said. “I’m ready to kneel in front of them and beg forgiveness -- in the name of the family.”

He lowered his head and appeared to be fighting back tears as he walked back up the driveway to his brick house.

Another uncle, who lives in Gaithersburg, Md., suggested there has been a longstanding rift in the family.

“We’ve got problems between family,” Alviz Tsarni told reporters outside his home. He did not elaborate on the nature of the problems but said he last talked to his nephews by phone about three years ago.

When asked what he would say to Dzhokhar, Tsarni said, “He’s not going to listen to me. They argue with us.”

He also expressed hopelessness about Dzhokhar’s fate.

“They will kill him. We know it. What’d done is done. He’s already dead,” he said.

Aunt not convinced

But not all family members are convinced the brothers are guilty of anything.

Maret Tsarnaeva is an aunt of the two brothers and lives in Etobicoke, outside Toronto. She told reporters she cannot offer any reaction to the news until she has seen convincing evidence that her nephews are really the perpetrators of Monday’s bombings and the killing of a Cambridge campus police officer overnight.

Tsarnaeva, who said she’s Chechen and is used to being set up by the police, said no one has come to her with anything that proves her nephews were behind any of it.

“If you have evidence, or if the FBI has evidence, why are you asking me if I believe they would do this?” she told reporters.

She said Dzhokhar came to the U.S. with his parents in 2002 and the family applied for refugee status. Dzhokhar’s brother and their two sisters stayed in Russia until they were allowed to come to the U.S. a few months later.

She also said her brother Anzor, the boys' father, was “a very loving, soft-hearted father.”