Both the original evaluation of 420 male and female defendants and this independent reanalysis of data gathered during the original study reveal that only a minority of drug-using defendants released pending trial were likely to be rearrested or fail to appear. Those who failed to appear for the first postrelease urine test or provided no urine sample were significantly more likely to be rearrested than those who tested positive for drugs. About 56 percent of those who failed to appear for the first postrelease urine test were either rearrested or missed court appearances compared to about 22 percent of those who showed up and tested negative and about 39 percent of those who tested positive. The multivariate analysis showed that those who failed to show up for postrelease testing were more likely to be rearrested than those who tested positive for drugs after release, even after controlling for criminal history, arrest charge, and other demographic factors. A pretrial urine-monitoring program may help separate low-risk, drug-involved arrestees from individuals who are at high risk of rearrest and failure-to-appear. 9 notes, 1 figure, 3 tables, and 19 references (Author abstract modified)