The extent of lethal gang violence in Chicago can be seen through statistics compiled by researchers at the Illinois Criminal Justice Information Authority. According to the Homicide Dataset, the number of gang-related killings did not exceed 100 in a given year until 1990; but the violence escalated rapidly in the early 1990's; in 1994, 240 gang-related killings were recorded in Chicago. The number of street gang homicides increased almost 30 percent from 1992 to 1993 and jumped nearly 45 percent from 1993 to 1994. Guns played a prominent role in most gang assaults. Between 1987 and 1994 in Chicago, firearms were used in 96 percent of all street gang homicides, 51 percent of aggravated batteries, and 70 percent of aggravated assaults. The research also shows that the age of offenders involved in street gang killings is declining. Over the 30-year period of the Homicide Dataset, 29 offenders between the ages of 10 and 14 were involved in street gang homicides. The data suggest that the greater use of semiautomatic and automatic weapons has contributed to the increase in lethal attacks by younger street gang offenders. To help police and other agencies better address the gang problem, the Authority developed two tools for identifying and predicting gang violence. Together, they compose the Early Warning System for Street Gang Violence. The first tool is the GeoArchive, a database of community and law enforcement information that can be used to plot gang activity. The other tool is the Spatial and Temporal Analysis of Crime software package. It locates clusters of criminal activity by automating such analytical functions as time-of-offense data analysis and manual pin mapping. Used with mapping technology, these two tools help create a computerized pin map that can be used for law enforcement planning and strategy.