Biometrics have a really long way to go before they can be used on life-saving equipment -- like firearms.
Imagine having to use voice recognition to open an emergency exit. Or a Retinal Scan to use the defibrillator on an ambulance.
When Cops are mandated to use "smart guns" as their duty sidearms, I'll be more accepting of possibly using one in the future.
Until then, they need to stop trying to inject unreliable technology where it can cost lives.