An 18-year-old assailant identified as Abdoulakh A. allegedly attacked and killed Samuel Paty, a history teacher from a Paris suburb, on 16 October. The assailant attacked Paty with a knife and then beheaded him while he walked home from school.

Previously, Paty had shown his students a cartoon of the Prophet Mohammad as part of a civics lessons on freedom of expression. The lesson sparked offense among some students’ parents, one of whom posted a video on social media lambasting the teacher, branding him a thug. For Muslims, any depiction of the Prophet is considered blasphemous.

Tribute planned for beheaded teacher in France; 11th person arrested https://t.co/wDMDTA533w pic.twitter.com/sGqeBHZyqZ

— Reuters (@Reuters) October 18, 2020

Students said Paty invited Muslim students to leave or look away while he showed the image—lest they take offense. Teachers’ unions and lawmakers hailed the teacher’s decision to confront challenging taboos in French society, according to Reuters. The president of the National Union of School Teachers, Jean-Remi Girard, told BFM TV that children need to understand that while blasphemy can shock, it is legal in France.

It is unknown whether the attacker, who was shot dead by police soon after the attack, saw the video. Police have detained 11 more people in connection with the killing. For French intelligence agencies, the attack has been a harsh wake up call. The attacker had a juvenile delinquency record but was not on any watchlists or intelligence files. The attacker has no known connection to Paty or the school where he taught.

On Monday, French police said that they raided the homes of dozens of suspected Islamic radicals in connection to the killing of Paty. Police will interview approximately 80 people who may have posted messages in support of the assailant, the BBC reported.

French police raid homes of suspected Islamic radicals after beheading of teacher Samuel Paty https://t.co/YQzsEmSy50

— BBC News (World) (@BBCWorld) October 19, 2020

“The profile of the attacker, as recounted by law enforcement officials, illustrates the difficulties security agencies face identifying would-be attackers who are often exposed to extreme ideology on the Internet and whose contacts with other Islamist militants, if they have any, may have been purely virtual," according to Reuters.

Online radicalization threats have increased since the emergence of the COVID-19 pandemic, especially as national lockdowns have forced many people to isolate at home, seeking refuge and community online.

“It can be all too easy for people to become radicalized without even leaving home," according to a report from American University’s Polarization and Extremism Research and Innovation Lab and the Southern Poverty Law Center, Building Resilience & Confronting Risk in the COVID-19 Era: A Parents & Caregivers Guide to Online Radicalization. "The proliferation of extremist spaces and online content has created new and powerful avenues for radicalization, especially for young people.” (Find out more about radicalization and successful counter-narrative strategies in the November 2020 issue of Security Management.)

The murder of Paty struck a chord with many French people—it echoes the attack on satirical magazine Charlie Hebdo in 2015, where 12 people were killed after the magazine published a series of cartoons of the Prophet Mohammad.

Last month, a 25-year-old man wounded two people outside the former Charlie Hebdo office.

Thousands of people gathered across France on Sunday to support teachers and defend freedom of expression, Reuters reported. The French government is working on a strategy to better protect teachers from threats.