LIANE HANSEN, Host:
NPR's Martin Kaste reports that even though alleged gunman Jared Loughner was caught at the scene gun in the hand, the case is not open and shut.
MARTIN KASTE: The first few hours of this investigation were described as organized chaos. That's certainly what Roger Salzgeber remembers.
KASTE: That was pretty hectic. I probably had my name taken down at least six times by different sheriff's department officers as I sat on the curb pretty devastated.
KASTE: Salzgeber was one of the men who tackled Loughner and one of dozens of firsthand witnesses to the crime. Eventually, he and his wife got their turns inside the sheriff department's RV, where they were interviewed at length. A deputy asked most of the questions, he says, with an FBI agent listening in. Then a few days later, they came to his house.
KASTE: A gentleman came out and went over our car one more time in excruciating detail looking, you know, for scratches or stray bullets, 'cause I think they have more or had more shell casings than they could find bullets.
KASTE: This attention to excruciating detail is remarkable given the magnitude of the case. The Pima County attorney's office says so far, victims and witnesses total about 150 people.
U: We got about 20 minutes left at the (unintelligible)...
KASTE: At the sheriff's department, deputies monitor live aerial surveillance video of the funeral of one of the shooting victims. Captain Frank Duarte says the investigation itself is now entering a new phase.
C: Most of the investigation at this point will now begin to do the forensics piece, doing up the research and all the pieces that you need to bring the puzzle together.
KASTE: With the physical evidence mostly gathered, attention is now shifting from what happened outside the Safeway to what happened in the days and weeks before the shooting. And Loughner's defense team will dig even further back.
P: The defense lawyer's job is to learn everything that there is to learn, that can possibly be known about her client.
KASTE: David Bruck is a clinical professor at the Washington and Lee School of Law. He's worked on similar high-profile murder cases as co-counsel for Loughner's new lawyer, Judy Clarke. He says Clarke most certainly already has private investigators on the case.
KASTE: There has to be a thorough, a truly exhaustive investigation of the defendants' background, his life, what - his road in life, where he came from, why he may have done this, what his informative experiences were. It's an investigation that goes back generations.
KASTE: Bruck says the investigators will want to know if mental illness runs in the family, but not necessarily in order to mount an insanity defense.
KASTE: The insanity defense means the person is legally not guilty, however, a guilty defendant still can and very often does present evidence at the sentencing part of the trial about mental afflictions that may have affected his blameworthiness at the time of the crime.
KASTE: Martin Kaste, NPR News, Tucson. Transcript provided by NPR, Copyright NPR.