Experts explain: How does an officer use a gun instead of a Taser?

The death of Duante Wright is sparking protests and outrage nationwide, and leading many to ponder one important question: How could that officer not know she had a gun in her hand, and not the non-lethal taser?  

While extremely rare, incidents like this one have happened before. 

The Associated Press reports there have been at least nine cases documented between 2001 and 2012.

"If you look at a lot of SWAT-operator folks, they normally wear their Taser on their thighs and firearm on their hip.  While you’re still using muscle memory, you're going to reach deeper down to grab the Taser than higher up," explained Peter Massey, a teacher in the criminology department at USF St. Petersburg. 

RELATED: Daunte Wright shooting: Officer grabbed gun instead of taser, bodycam video released

Massey notes officers usually train more often with their gun over their taser.  

Dan Linksey, a former Boston police chief, says that type of training, along with so-called tunnel vision, likely played a role. 

"The challenge is, when you're under stress, if you haven't trained enough, you lose fine motor skills.  You aren't hearing things, you aren't seeing things," Linksey said.  "The reason you have tunnel vision is you're in fear."
 
The officer who pulled the trigger, Kim Potter, has resigned.