The new study was done in order to validate previous findings, determine the threshold below which air quality and crime rates do not correlate, and to find out the cumulative or delayed effects of air quality. Novel data were collected which included measures of 12 air quality variables of 2 different types of crimes, i.e., 'hot crimes' which were violent and aggressive, and 'miscellaneous crimes' which were of a more equivocal nature. When crime counts were grouped by type and location and then graphed by day of the week, it appeared that a weekly crime pattern did exist. The pattern of miscellaneous crimes was similar to that of hot crimes -- advanced by 1 day. Power spectral analyses suggested the existence of an additional cycle in the value of miscellaneous crime data, having a period of 3.5 days. These findings were consistent with the 1974 study. Results also suggest that a correlation between selected air quality variables and crime count maintained its validity when applied to a novel sample of data. Although climatic variables by themselves were of little importance in the prediction of miscellaneous crimes, they were particularly important in the prediction of hot crime--again reinforcing the 1974 study findings. An examination for thresholds of effects for air variables found a 5 percent average increase in predictive power when maximum values instead of daily averages were used for air variables. This may suggest a threshold for the activation of the mechanism which links air quality to crime count. Analysis of cumulative or delayed effects of air quality variables upon crime count showed an 8.7 percent increase in predictive ability when information on air quality for the previous day was added to information used to construct predictor equations, and a 4.9 percent increase in predictive ability when information for 2 preceding days was added. The study may find immediate practical value in more accurate manpower deployment of police to coincide with crime rate predictions, thus reducing overtime and call-ups. Seven appendices include graphs of raw data, Los Angeles air quality monitoring procedures, and crime classifications. Thirty-five data tables and 23 references are provided.