The California Substance Abuse and Crime Prevention Act (SACPA) of 2000 targeted nonviolent offenders who have a history of substance abuse and were primarily charged with misdemeanor or felony possession, excluding selling charges, for diversion from incarceration into community-based substance abuse programs. The two sites selected for this study (the El Monte Drug Court in Los Angeles County and San Joaquin County Drug Court) had SACPA programs that differed from each other and from the Drug Court model. The data for the outcome analysis were collected from administrative databases and from paper files where necessary and available. The data link an individial's criminal activity data, treatment data, and other program activity data. The outcome analysis consisted of Drug Court and Substance Abuse and Crime Prevention Act (SACPA) samples from San Joaquin and El Monte (Los Angeles) counties. Part 1, San Joaquin County Data, had a total of 725 participants and Part 2, El Monte (Los Angeles) County Data, had a total of 587 participants. The Drug Court cohort included pre- and post-SACPA Drug Court participants. The pre-SACPA Drug Court participants included all those who entered the Drug Court program July 1998 through June 1999 and included 202 participants in San Joaquin and 127 participants in El Monte. The post-SACPA Drug Court participants included all those who entered the Drug Court program in July 2002 through June 2003. This sample provided 128 participants in San Joaquin and 147 participants in El Monte who experienced the Drug Court program after any changes in eligibility and Drug Court processes due to SACPA, as well as allowing for outcome data for three years post-program entry. The SACPA samples in San Joaquin and El Monte consisted of all SACPA participants who were first time enrollees in SACPA programs between July 2002 and June 2003. These samples included 395 participants in San Joaquin and 313 participants in El Monte who experienced a reasonably well-established SACPA program while still allowing three years of outcomes post-program entry. The data for both San Joaquin county and El Monte (Los Angeles) county include the demographic variables age, race, gender, and drug of choice. Drug Court Treatment variables include dates or number of group sessions, dates or number of individual sessions, dates or number of days in residential treatment, other Drug Court service dates and types. Substance Abuse and Crime Prevention Act (SACPA) Treatment variables include dates or number of group sessions or episodes, dates or number of individual sessions or episodes, dates or number of urinalysis tests, dates or number of days in residential treatment, and other SACPA service dates and types. Other variables include arrest data, new court cases data, jail data, prison data, and probation data.