Study shows gang figures related



WASHINGTON (AP)—Gang-related killings in Chicago have risen dramatically since 1965, and that’s directly related to gang members’ increased firepower, a study released Sunday said.

‘‘Virtually the entire increase in the number of street gang-motivated homicides seems attributable to an increase in the use of high-caliber, automatic, or semiautomatic weapons,’‘ the report for the National Institute of Justice found.

The country’s third largest city saw the number of gang killings rise from 11 in 1965 to 133 last year.

Researchers reviewed gang murders from 1965 and non-lethal incidents from 1987 through 1990 from Chicago Police Department records. Four of the city’s 40 major gangs account for about half of the 38,000 gang members, the researchers found. They made up most of the gang-related crimes and homicides from 1987-90.

Gang crime is not random, occurs in specific neighborhoods and is concentrated in limited time periods, said the study for the Justice Department’s research agency.

‘‘Some street gangs spent much of their time defending or expanding their turf, while others were actively involved in the business of illegal drugs,’‘ the report said.

‘‘Programs to reduce street gang-motivated violence must recognize these differences. For example, a program to reduce gang involvement in drugs in a community in which gang members are most concerned with defense of turf has little chance of success.’‘

Among the study’s major findings:

_Each of the four biggest gangs was responsible for at least 1,000 criminal incidents recorded by police from 1987-90.

_From 1987-90, there were 288 gang-related homicides; 8,828 non-lethal violent offenses such as assault and battery; 5,888 drug offenses; and 2,081 other offenses.

_In 1987, one gang homicide occurred for every 44 incidents of gang violence. That rate was 1:20 in 1990.

_The two most dangerous communities (East Garfield Park and Humboldt Park) had a mean annual rate of gang crimes 76 times the mean annual rate in the two least dangerous areas (Mount Greenwood and Edison Park).

_Gang killings were concentrated in two corridors on the city’s northwest and southwest sides.

_The most lethal street gang hot spots are along disputed boundaries among small street gangs.

The report was prepared by Carolyn Rebecca Block, an analyst at the Illinois Criminal Justice Information Authority, and Richard Block, professor of sociology at Loyola University in Chicago.