A new deputy joining Andy and Barney suggests their manner of enforcing the law is flawed. They aren't meeting quotas nor making arrests pertaining to certain ordinances. Barney, after quitting, asks for his job back, explaining his qualifications and insisting that law enforcement is not about numbers, it's about people.

The LAPD are piloting a mathematical program developed by UCLA that predicts the probability of a crime occuring.

Disaster strikes in a New York tunnel as explosions collapse both ends of it; a combustion ensues.

War in the 21st century will be waged on many fronts -- one of which will be a digital battlefield with no guns or bombs.

Photojournalist David Handschuh recalls his experience during the September 11, 2001 attacks. He was taking pictures near the South Tower when it collapsed, which hurled him half a block and shattered his leg. He describes his experience being rescued.