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Three years ago, al-Qaida’s magazine, Inspire, published an article titled, “Make a bomb in the kitchen of your Mom.” The article explained how to build a pressure-cooker device like the ones that blew up last week at the Boston marathon. But the recipe left out the most important ingredient. To make a bomb in your mom’s kitchen, the first thing you need is an inattentive mom.

That’s what Tamerlan and Dzhokhar Tsarnaev had. We don’t yet know where or when they made the bombs they’re accused of planting at the marathon. But we do know that their father, Anzor Tsarnaev, and their mother, Zubeidat Tsarnaeva, had plenty of warnings that Tamerlan was becoming dangerous. Tamerlan was a human pressure cooker loaded with zeal, violence, and destructive ideology. His parents, blinded by adoration and excuses, refused to see it.

Most people who met or knew Tamerlan, including family members, say he was a jerk. His dad, however, insists Tamerlan was “kind” and “very nice.” Anzor “lost control over that family quite a time ago,” says his brother Ruslan. In every interview, Anzor claims to know exactly what his kids have been up to, though he hasn’t seen them since he moved back to Dagestan a year ago. He also claims, falsely, that Tamerlan “was never out of my sight” during the young man’s visit to Dagestan last year. According to Anzor, Tamerlan was such a boxing stud that “in the U.S. everyone knows he is a celebrity.” When Anzor left Boston, he asked Tamerlan to keep an eye on Dzhokhar. He thinks the elder brother has been keeping the younger one away from bad influences.

Tamerlan’s mother is just as deluded. She swears Tamerlan and Dzhokhar couldn’t be involved in a bomb plot because “my sons would never keep a secret.” Instead of correcting Tamerlan’s conspiracy theories, she swallowed them. According to one of her spa clients, Zubeidat recently called the 9/11 attacks a U.S. plot to stoke hatred of Muslims. “My son knows all about it,” she allegedly told the client. Zubeidat also says the FBI has been watching her family constantly for years, which the FBI denies. Last year, she was arrested, but apparently never prosecuted, for shoplifting $1,600 worth of clothes.

Anzor and Zubeidat were given several warnings that Tamerlan was headed for trouble. Sometime between 2007 and 2009, Tamerlan and Zubeidat turned to religion. Zubeidat became observant, but Tamerlan became intolerant and hostile. He pushed his strict views on the rest of the family, causing tensions. When his sister married a non-Muslim, Tamerlan didn’t accept the man. Tamerlan’s uncle, Ruslan, perceived a change in his nephew’s personality. Ruslan says a family friend told him in 2009 that a Muslim convert had “brainwashed” Tamerlan.

The tension exploded when Tamerlan, in a conversation during that period, called Ruslan an “infidel.” Tamerlan also challenged another uncle, Alvi Tsarni, to a fight. No one in the family has explained what words ensued between the parents and the uncles, but both uncles cut off contact with the Tsarnaevs. Ruslan says his beef was with “the way they were bringing the children up.” Anzor, unchastened even by the marathon bombings, says the uncles don’t really know his kids. “They are just blabbing what they know nothing about,” he told the New York Times on Friday.

Around this time, Tamerlan was arrested and charged with domestic violence for hitting his girlfriend. “Yes, I slapped her,” he told police. The case was eventually dismissed, and Anzor brushed it off. “He hit her lightly,” Anzor told the Times. “There was jealousy. … In America you can’t touch a woman.”

In early 2011, two FBI agents, provoked by an alert from Russian intelligence, came to the Tsarnaevs’ apartment to speak to the family about Tamerlan. Zubeidat says the agents explained that Tamerlan was visiting “extremist sites” and that “they were afraid of him.” She says Tamerlan answered the agents defiantly, "I am in a country that gives me the right to read whatever I want and watch whatever I want.” Anzor shrugged off the warning: "I knew what he was doing, where he was going. I raised my children right.” Zubeidat says the agents investigated Tamerlan only because "he loved Islam."

So the warnings passed. When the marathon bombs exploded, and videos implicated Tamerlan and Dzhokhar, the uncles acknowledged the evidence, but the parents didn’t. They didn’t just stammer, as many parents would, that their sons couldn’t have done it. They declared that the young men had been “set up,” and they hurled conspiracy theories at the authorities. “The police are to blame,” said Anzor. “Being cowards, they shot the boy dead. There are cops like this.” He denounced the pursuit of his sons by law enforcement as “a provocation of the special services who went after them because my sons are Muslims and don’t have anyone in America to protect them.” Zubeidat said the authorities “wanted to eliminate [Tamerlan] as a threat because he was in love with Islam.”

Anzor’s sister, Maret Tsarnaeva, echoed these self-deceptions. “Growing up, within the family, everything was perfect,” she told reporters on Friday. Her nephews had no motive to bomb anyone, she insisted: “For what beliefs? I don’t know them to have any strong beliefs.” She concluded that “our boys were framed.” When reporters showed her video evidence implicating them, she replied: “The picture was staged.”

Neighbors and congregants at Tamerlan’s mosque had warnings, too. In November 2012, he angrily rebuked a merchant in Cambridge for advertising Thanksgiving turkeys, which Tamerlan viewed as an affront to Islamic law. At Friday prayers, he disrupted and criticized a sermon that defended the celebration of Thanksgiving and July 4. Two months later, he interrupted an imam who suggested that Martin Luther King Jr., like the Prophet Mohammed, was worthy of emulation. Tamerlan protested that King was “not a Muslim,” and he called the imam a “Kafir,” or non-believer. Some of the congregants threatened to expel Tamerlan, but apparently, none of them reported him to the authorities, since, as far as they knew, he hadn’t preached or committed any violence.

You can’t expect witnesses to report every fanatical outburst to the FBI. But when family members are repeatedly exposed to signs that a loved one is drifting into the vortex of violent extremism, they have a duty to intervene, or at least to alert someone. If they don’t, and the fanatic becomes a killer, they bear an awful responsibility. If they deny that responsibility by accusing the police and the government of anti-Islamic conspiracies, they forfeit our sympathy, our respect, and our trust. Police your family. Police your congregation. Police your community. If you don’t, the rest of us will do it for you.

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