Intelligence analysts first break down police reports, court dockets, and other information to record names, addresses, vehicles, associates, property, modus operandi, etc. in a database. They then compare and link database records; for example, connecting two people by an address they once shared or two crimes by the type of weapon used. The software plots the links graphically. Most programs use a system of "car," "person," "house," and other icons, connected with colored broken lines to reflect the nature and strength of relationships. Spatial or mapping analysis is often used to pinpoint crime patterns. Most software includes a "failsafe" against entering duplicate information. Agencies can customize the software according to their needs. Analysts can select and code information to be Internet-viewable by analysts and investigators from other agencies or patrol officers in the field. As fast and effective as database-enabled link charts are, their structure poses one problem: it does not address the subtleties of human language and relationships that appear in police reports, witness statements, court documents, or other unstructured data. Some analysts use "text extraction" software that allows them both to obtain data and to analyze it in accordance with its context. Various commercial software on the market is profiled. 3 illustrations