What's the movement behind the groups of armed US civilians patrolling the US-Mexico border?Read more
US gun laws
A rise in hate crimes against minority groups has lead some to take up weapons for themselves.
Gun-wielding police in the US state of Colorado have been filmed confronting a man picking up trash on his lawn.
A teacher and a pupil at Marjory Stoneman Douglas High School gave people a focal point for their grief and curiosity.