3-year-old girl kills 4-year-old sister after finding loaded handgun in Houston

A Houston girl shot and killed her older sister after finding a semiautomatic handgun at the apartment they were visiting.

The girls were at the apartment with their mother, stepfather and three other adults, and the 3-year-old girl found the loaded weapon and fatally shot her 4-year-old sister when they were briefly left alone in a bedroom, reported KTRK-TV.

"You've got to make sure you're a responsible gun owner," said Harris County sheriff Ed Gonzalez. "Secure your weapons in a safe place. It's got to be more than just to tell the kids not to touch the weapons."

The sisters' mother and stepfather each believed the other was supervising the girls.

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"It just seems like another tragic story of a child gaining access to a firearm and hurting someone else," the sheriff said. "This time it was a fatal shot, appears to be to her sibling."

Investigators did not say who owned the weapon, and it's not clear whether any charges will be filed in the shooting.