A Norwegian man suspected of killing his stepsister and then storming an Oslo mosque with guns appeared in court Monday with a smirk on his bruised face as evidence grew that he sought to emulate attacks by white supremacists in the U.S. and New Zealand.

Security experts believe Philip Manshaus is the latest example of an extremist who was radicalized by far-right conspiracy theories spread online, particularly the "great replacement" theory, which falsely warns of a "genocide" in which white people are being replaced by immigrants and Muslims.

"Magnus Ranstorp, the lead terrorism researcher at the Swedish Defense University, said the rise of violent far-right extremism is being driven by a complex overlapping of elements, including hateful rhetoric and conspiracies on social media and "old Nazis combining with the alt-right, combining a race war with a cultural war."

Adding to that are state actors, like Russia with its propaganda outlets, and President Donald Trump seeking to sow tensions and break down trust in established elites and the media.

"The leader of free world is part of the problem," Randstorp said.

"We are in a hybrid threat environment — we are not in peacetime," Randstorp added. "Liberal democracy is under threat."