“The online sphere is 100% key to these attacks,” said Hans-Jakob Schindler, the former coordinator of the United Nations Security Council’s panel on Islamic State and al Qaeda. […] The man then connected online with Islamic State sympathizers and spread extremist content, he added. Acting on the group’s advice available online, he bought a kitchen knife—rather than one that might draw officials’ notice—and stabbed the victims’ necks to increase the likelihood they would die, said Schindler, who is now senior director at the Counter Extremism Project, a nonprofit that combats extremist ideologies.