As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING APPROACH INTO LAS WHEN LANDING GEAR SELECTED DOWN, THE RED GEAR UNLOCKED LIGHT REMAINED ON WITH ALL THREE GEAR SAFE LIGHTS ILLUMINATED. THE RT MAIN GEAR DOWNLOCK SWITCH WAS FOUND DEFECTIVE. THE SWITCH WAS REPLACED AND ADJUSTED PER THE CV-580 MM.