Brad Bushman, professor and researcher of communication and psychology, spoke on Bloomberg about what causes mass shootings.

"When a mass shooting does occur, people try to identify the cause, but they're extremely complex, and they're caused by a number of factors," said Bushman.

Three main factors people discuss after a mass shooting include mental illness, violent media and easy access to guns. Bushman dispeled some myths about these factors and presented facts backed research.

Watch the full video on Bloomberg.