As investigators uncover details about what motivated the Boston Marathon bombing suspects, an early report suggests the two brothers learned their violent tactics online from an English-language Al Qaeda propaganda magazine.

Dzhokhar Tsarnaev, who is in custody, reportedly told investigators that he and his older brother learned how to create pressure cooker bombs from Inspire, an online magazine published by the Yemen-based Al Qaeda in the Arabian Peninsula (AQAP).

“Inspire is one of many jihadi publications in English, and it’s done a lot of things slightly better than its predecessors,” says J.M. Berger, author of Jihad Joe: Americans Who Go To War in the Name of Islam. “But its most meaningful innovation has been to combine both the incitement to jihad with the how-to of terrorism.”

AQAP began publishing Inspire in 2010, and its first issue included a now infamous article titled “Make A Bomb in the Kitchen of Your Mom” that instructed would-be violent jihadists to use materials commonly found in a household kitchen, such as a pressure cooker. Analysts suggest the Tsarnaev brothers may have been inspired by this article.

Aaron Zelin, a fellow at the Washington Institute for Near East Policy who studies Al Qaeda propaganda, says a typical issue of Inspire includes a few consistent components: a letter from the editor that outlines the issue’s theme and how AQAP is going after the “enemies of Islam”; an English translation of official AQAP statements; quotes from influential people dubbed friends or foes of Inspire or AQAP; articles about U.S. foreign policy or Yemen; a resource manual titled “Open Source Jihad” that explains violent techniques and guerrilla tactics; and at the end, instructions on how to contact or contribute to the magazine.

Not all of the ideas for waging jihad are as effective as “Make A Bomb in the Kitchen of Your Mom.” Inspire‘s Spring 2013 issue included instructions for how to cause traffic accidents by pouring liters of “lubricative oil” on the curves of U.S. highways. “We all agree that the Kuffar [unbelievers] chose the wrong path,” the article reads. “Now it’s due time for their vehicles to also leave the right path. Demolition Derby Style.”

When Inspire first came out, “the media went crazy,” says Berger, with news outlets from Fox News to Gawker highlighting its slick packaging and American idioms. But that attention and distortions about the magazine he says also expanded its reach and magnified its importance.

The magazine was the brainchild of American citizen Samir Khan, who was killed in the September 2011 drone strike that targeted radical cleric and American citizen Anwar al-Awlaki. Since Khan’s death, the magazine’s quality has declined, says Zelin. “Though they have continued to publish, they do so at random intervals and the production quality and editing isn’t as good.”

But Berger suspects the Boston bombings will again elevate the magazine’s influence. “They’ve never had a successful attack attributable to Inspire, and now they do.”