Homeland Security experts consider Southern Nevada a high-risk target for terrorist attacks.

Homeland Security experts consider Southern Nevada a high-risk target for terrorist attacks. As such, we are one of 30 major cities nationwide that actually monitor the air for biological weapons. The program is called BioWatch.

BioWatch has drawn criticism since it began five years ago. Just this week, members of a Congressional subcommittee heard it characterized as a "parasite" by the local public health officials tasked with running it.

The early warning system to detect airborne pathogens may look good on paper. The challenge is in the practice.

In a city surveilled by thousands of eyes in the sky, the federal government has harnessed a second sense to sniff out terrorism. The program, known as BioWatch, is designed to screen the air for biological weapons -- agents like anthrax, plague and smallpox. It's like an air monitoring filtration system.

Watch the I-Team: Bio Weapons Monitor System Draws Criticism video at the LasVegasnow website.