Approximately 52 percent of the 3,232 felony defendants interviewed actually entered the experimental SPR study. They had an average of five prior arrests and two prior convictions. Twenty-two percent faced criminal charges for burglary; 12 percent, for theft; 11 percent, for assault; 10 percent, for robbery; and 10 percent, for drug-related crimes. Most were young (16 - 26-years-old), male (89 percent), and unmarried (89 percent). Defendants were randomly assigned to two test groups: a supervision-only group and a supervision-plus-services group. The median length of supervision was 48 days. During that time, an average of 16 telephone contacts and 12 face-to-face contacts were made by staff per defendant. Eighty percent met the required number of weekly phone contacts, but only 60 percent met the required number of face-to-face contacts. Eighty-six percent appeared for all of their required hearings; fugitive rates were low in all three sites, ranging from 2 percent in Milwaukee and Portland to 8 percent in Miami. Based upon data collected for the SPR clients and upon other felony bookings, SPR hypothetically saved 93,408 detention days, or a total of 256 beds, for the three sites. Three simulations are presented to illustrate how SPR can add or reduce criminal justice costs. Two references are included.