lone wolf

A gunman wielding an assault-type rifle and a handgun took hostages and opened fire inside a crowded Florida nightclub, killing approximately 20 people and wounding 42 others before dying in a gunfight with SWAT officers, police said Sunday.

As the U.K. marks the tenth anniversary of the July 7 London bombings, there is a sense that what was a terrible new phenomenon in 2005 has become increasingly prevalent.