Is America ruled by fear? Four recent harmless mistakes result in four more horrific shootings. Why has the US become a place where people shoot first and ask questions later?
Shot for knocking on the wrong front door
Recovering: The man who shot Ralph Yarl, 16, has now been charged with criminal offences. Glossary
Innocuous - Harmless.
Lobby - Lobbyists seek to influence politicians and lawmakers on specific issues, such as farming or healthcare.
Constitution - A document that sets out the fundamental rules according to which a country is governed, which are usually difficult to change.
Paranoia - The belief, often with no solid basis, that you are being harassed, betrayed or persecuted by others.
Sociologist - Someone who studies human social behaviour. Modern sociology was developed by European thinkers in the 19th century, but it is also based on the writings of African American thinkers like W. E. B. DuBois.
Persecution - Ill treatment and oppression, especially due to a person's beliefs or race, gender, religion, sexual orientation or other factors.