It all started with a chain email.

“There are lessons indoctrinating children with Islam and verses of the Quran along with the United Nations Agenda,” a woman named Ginger Russell wrote before quoting from a high-school level world history lesson she said promoted a “loving kinder Islam.”

Russell sent the email in October 2012 to school board members and officials in Irving, Texas with the subject line “IRVING ISD INDOCTRINATING ISLAM,” according to a Dallas Morning News report from that time. The newspaper reported that the email prompted the district to launch an investigation into whether the curriculum it used was too pro-Islam.

Just under three years later, a 14-year-old Muslim student at Irving’s MacArthur High School was arrested for bringing a homemade clock to class that police thought looked like a “movie bomb.”

The Irving School District’s 2012 investigation into whether the curriculum it was using was too sympathetic to Islam, in addition to the mayor of the city’s recent anti-Sharia crusade, has taken on new significance in the wake of Ahmed Mohamed’s arrest. The high schooler ultimately faced no charges for bringing his invention to class but remained suspended Friday. Mohamed’s father said Thursday night that his son does not plan to return to public school, anyway.

At issue for Irving’s school board back in 2012 was CSCOPE, a curriculum developed by a group of state-run education service centers that has been criticized by some as having an anti-American bias, according to the Austin American-Statesman.

Critics of CSCOPE pointed to outdated lesson plans that asked students to consider whether the British may have considered those who carried out the Boston Tea Party to be terrorists, according to The American-Statesman. The Dallas Morning News reported that the chain email cited that lesson plan and further alleged that the curriculum conflated the Red Cross and Islamic Red Crescent.

The chain letter unnerved district officials enough for them to contact Region 10, a company that administers CSCOPE. The Dallas Morning News reported that ehe company’s director of instruction, Jan Moberly, was dispatched to Irving to share with the board the results of an investigation into whether the curriculum had a pro-Islam bias.

Moberly told the board she hired a “very socially and fiscally conservative” former social studies teacher who “watches Glenn Beck on a regular basis” and instructed her to review curriculum materials for anything “the least bit controversial,” according to the report.

Here’s what the conservative reviewer found, according to the Dallas Morning News: Christianity got twice as much attention in the curriculum as any other religion and, if there was any Islamic bias in the curriculum, it was “bias against radical Islam.”

h/t Slate