Concealed Carry Permit Holder may have stopped North Las Vegas shooting that left three people dead

UPDATE: The Las Vegas Review Journal has this:

After the shooting, the couple headed toward a nearby Wal-Mart, where Jerad Miller was confronted by Joseph Robert Wilcox, 31, of Las Vegas. Wilcox was legally carrying a concealed pistol. Wilcox was unaware that Amanda Miller, who was pushing a shopping cart, was involved in the incident and “lying in wait,” the official said.

She slipped behind Wilcox and shot him at close range.
“He had no idea the wife was walking behind him,” the police official said of the murdered man. “This guy (Wilcox) was not some idiot with a gun. To me, he was a hero. He was trying to stop an active shooter.”
It wasn’t immediately clear if Wilcox fired a shot, or if he hit Jerad Miller before he died. . . .

Even though Wilcox failed to shot these killers, he appears to have delayed them and given others a chance to escape.

ORIGINAL POST: It appears as if two people killed two police officers and then a concealed carry permit holder who tried to stop the two killers as they went to a nearby Walmart.  Immediately after the exchange of fire with the permit holder the killers committed suicide.  Waiting for more information.

From the UK Daily Mail:

The two suspects shot then shot dead a a civilian who is believed to have been carrying a concealed firearm and had opened fire on them as they ran into the Walmart, Deputy Sheriff Kevin McMahill said during an afternoon press conference. . . .

From the Australian Yahoo News:

The attackers then headed to a nearby Walmart store, exchanging gunfire with and ultimately killing a civilian who was carrying a concealed weapon. . . . 

The Las Vegas Review Journal reports:

One unconfirmed report is that the two exchanged gunfire with a citizen who was carrying a concealed weapon, and that one of the shooters was injured. . . .