Tamerlan Tsarnaev, one of the two suspected masterminds behind the Boston Marathon bombings earlier this year, had multiple subscriptions to publications that preached white supremacy and and conspiracy theories, BBC News reports.

Once the world learned of the identities of Tsarnaev and his brother, Dzhokhar, both were depicted as radical Islamists independent of a terrorist a group. When Dzhokhar was finally captured by police after hiding out in a boat, they found a note scribbled on the inside that read "I can't stand to see such evil go unpunished. . . . We Muslims are one body, you hurt one, you hurt us all."

However, as the investigation into both brothers continued, authorities discovered that the elder brother, Tamerlan, had been reading up on material that supported several controversial ideologies in addition to the militant Islamist websites they had visited.

Some of the literature was on mass killings and accused the Oklahoma City bomings and September 11 attacks as government conspiracies. The writing discussed motivations behind mass murder and explored how murderers carried out their acts calmly. Another publication discussed "the rape of our gun rights."

Tamerlan had been taking notes on white supremacist ideology. One publication even suggested that "Hitler had a point."

According to Dzhokhar's message left in the boat, what was most influential was probably the material analyzing US drones and Guantanamo Bay.

Both Tsarnaev brothers grew up in Chechnya, a republic of Russia torn apart by violent Islamic insurgency. The last ten years of their lives were spent in Cambridge, Massachusetts.

Nicole Mossalam, a spokesperson for Tamerlan's mosque in Cambridge, labeled him as a "Muslim of convenience," describing him as an angry young man who held tightly onto the Muslim faith but lacked in other departments like praying and volunteering in the community.

Officials are also investigating if the brothers had been influenced by other family members to carry out the attacks. The chairman of the House Intelligence Committee in Washington believes that their mother, Zubeidat Tsarnaev, influenced the radicalization of her sons but she has denied those allegations.