STEVE INSKEEP, Host:
We begin our coverage with NPR's Martin Kaste.
MARTIN KASTE: The Pima County Sheriff's office says Jared Loughner arrived at the Tucson Safeway by cab. For a time, investigators suspected the driver of being an accomplice - an idea they later dropped. Thirteen minutes after Loughner's arrival, at 10:12 a.m., the first 911 calls came in.
(SOUNDBITE OF 911 CALL)
U: Hello, 911, there was a shooting at Safeway, where Gabrielle Giffords was.
KASTE: It didn't take long before the system was flooded with calls from around the shopping complex.
U: Who? Okay, and there's other people that are injured?
U: Many people. There's multiple people shot.
U: Okay. Oh, my God.
KASTE: FBI director Robert Mueller.
KASTE: I believe we have an indication that he attended a similar event.
KASTE: Director Mueller wouldn't speculate about motivations, but he did point a finger at what he called inciteful speech on the internet.
KASTE: And that absolutely presents a challenge for us, particularly when it results in what would be lone wolves or lone offenders undertaking attacks.
KASTE: And yet, it could have been even worse. The shooting stopped when it did, say authorities, because of the intervention of a handful of citizens. Patricia Maisch is one of them. Sitting outside her home on Sunday evening, a desert sunset to her left, she recalled those long moments on Saturday morning when the gunman drew near.
KASTE: I was laying on the ground, and I was wondering how it was going to feel to be shot.
KASTE: But then, she says, the gunman was suddenly on the ground next to her, tackled by two men.
KASTE: And somebody yelled, get the gun. So I immediately knelt up over him, 'cause he was right there on - almost on top of me, so he was reaching in his pocket and - with his left hand - and he pulled out a magazine, or a clip, and so I was able to grab the magazine and get a hold of it so that he couldn't.
KASTE: Martin Kaste, NPR News, Tucson.