With baseball caps pulled low over their eyes and scarves wrapped tightly around their mouths, the young men huddled at sundown to pay tribute to a killer.

More than a dozen had come to the scene where their “brother” was shot dead by police after he sprayed gunfire outside a cafe and a synagogue. Now they would give him a proper — and defiantly public — send-off: quiet prayers, followed by repeated chants of “Allahu Akbar” and the raised-index-finger salute of the Islamic State.

“May Allah show you grace,” read the handwritten sign they taped to the bullet-scarred apartment building where 22-year-old Omar Abdel Hamid el-Hussein fell. “Rest in peace, Captain.”…

“The Brothas is dominated by young men without an education who feel they are not accepted in society,” said Aydin Soei, author of “Angry Young Men,” a book about gangs and inner-city life in Copenhagen. “They are not good Muslims and they know it. But Islam is part of their identity. They have a group identity of everyone being against them and being underdogs. In that identity, Islam means something.”