EXPLAINER: How does someone confuse a gun for a Taser?

The jury deliberating at Kim Potter's manslaughter trial in the shooting death of Daunte Wright asked a judge whether the officer's handgun could be freed from an evidence box so they could hold it.

Their question Tuesday went to the heart of the former police officer's claim that she made a tragic mistake when she grabbed her gun, instead of her Taser, and shot Wright during a traffic stop April 11 in the Minneapolis suburb of Brooklyn Center.

Prosecutors had highlighted the differences in the look, feel and weight between Potter's gun and Taser, and had promised jurors they would be able to handle them during deliberations.

Taser-gun mix-ups are rare but have happened in several states in recent years.

Here are some questions and answers about such incidents:

HOW FREQUENTLY DOES THIS HAPPEN?

Experts agree that such incidents are rare and probably happen fewer than once per year throughout the U.S. A 2012 article published in the monthly law journal Americans for Effective Law Enforcement documented nine cases dating back to 2001 in which officers shot suspects with handguns when they said they meant to fire stun guns.

The phenomena of “weapons confusion” is well known in policing, according to the prosecution's use-of-force expert, Seth Stoughton, a professor at the University of South Carolina School of Law. He testified that he knew of “fewer than 20” cases since Tasers were introduced in 1993 in which officers used their firearms instead. He said the manufacturer has taken steps to try to prevent such errors and it's become an important part of the training officers get.

WHY DOES IT HAPPEN?

Reasons that have been cited include officer training, the way they carry their weapons and the pressure they feel during dangerous and chaotic situations. To avoid...