The attacks on Copenhagen could be the first copycat crime following the murders at French satirical magazine Charlie Hebdo in January, said Charles Sennott of GlobalPost and The GroundTruth Project on Boston Public Radio.

Two people died Saturday when a 22-year old gunman opened fire on a forum celebrating free speech and a synagogue. He was later killed in a shoot-out with police.

"There is this sense that these lone gunmen, as the Prime Minister is portraying this gunman in Copenhagen, are inspired by ISIS," Sennott said.

The attacks are a profound challenge to the idea northern Europeans have of themselves as free and open societies, said Sennott, and in their response they will have to balance security concerns with their commitment to those ideals.

"They are experiencing the trial of terrorism, which tries to force us to change the way we carry ourselves in the world," Sennott said.

"Part of the fight against terrorism is the battle of ideas. How do you hold on and hold true to what you believe in?" he continued.

To hear more from Charles Sennott, tune in to his full segment on Boston Public Radio above.