Most national law enforcement databases track criminals and suspects - not victims - so officials say they are taking steps to protect the victims' privacy.

Facebook and Twitter posters also examined Internet postings in order to track suspects.

The landmark legislation expanded the government's power to use eavesdropping, surveillance, access to financial and computer records and other tools to track terrorist suspects.

But they said four transit officers helped to track several suspects to Roseland, where two of them were arrested.

The ID cards also make it easier to track suspects within the city.

However, they are trained in how to safely track and detain suspects until police arrive.

Policeware is a name given to keyloggers and other tracking programs used by law enforcement agencies to track suspects.

The system allows operators to track multiple suspects at once and can automatically monitor user-designated zones.

At present, a manual system is used to track suspects.

Knowing how to translate gang markings makes it easier to track suspects.