Warning: some of the audio in this segment is disturbing. 

A woman in Minnesota turned to Facebook live in the moments after her boyfriend Philando Castile was fatally shot by a police officer in a traffic stop on Wednesday.

And on Tuesday, another police shooting was caught on video, capturing a police officer shooting a man named Alton Sterling outside of a Louisiana convenience store.

Norm Stamper, former Seattle Chief of Police and author of To Protect and Serve: How to Fix America's Police (Nation Books, 2016), discusses these recent events.

Scared cops are impulsive cops. They can't perceive threats accurately. Oftentimes they can’t even shoot straight, says @NormStamper.

— Brian Lehrer Show (@BrianLehrer) July 7, 2016