Good guy with a gun intervenes in attempted mass killing, blows gunman away. Neighbors say it...

Authorities said an armed 26-year-old Zachary Arnold, a resident at the Fort Smith, Arkansas, apartment complex where the event occurred, was outside his building Saturday morning when he began screaming for residents to come outside.

Arnold, who was armed with a rifle, was first met by an elderly neighbor, 87-year-old Lois Hicks.

One neighbor told the station that Hicks and another elderly woman came out to "console" Arnold when he opened fire.

"There were two older women, both had come out," the neighbor explained. "One of them had ran back in, and the other one ran back in, but she didn't close her door, then he walked in and did what he did."

After fatally shooting Hicks, authorities said, Arnold continued to fire rounds from his rifle and tried to persuade other residents to come out of their homes.
One neighbor, who remains unnamed at the time of this reporting, grabbed his own rifle and bravely exited his apartment to put a stop to the mayhem. The male neighbor fatally shot Arnold, immediately ending the would-be mass killing.

A resident told the station, "If he didn't do that, who knows how much worse it could have gotten."

It currently remains unknown what prompted Arnold to storm his own apartment complex, and the incident remains under investigation. It is unclear whether the unnamed good Samaritan will face charges in connection with the shooting.