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Rick Scott, Governor
Florida Department of Corrections, Secretary Julie L. Jones

Florida Department of Corrections
Julie L. Jones, Secretary

Data and Methods: Data Sources

The Department routinely receives data only on those offenders who are recommitted for either a term of supervision or imprisonment by the state agency. Information on those sentenced to local probation or jail is not available. Therefore, the Department can reliably report only the rate of recidivism based on new offense and commitment data drawn from Department records. Data for this report were extracted for the Bureau of Research and Data Analysis from the Department's Offender Based Information System (OBIS).

Sources and Case Selection

Releases, Offenses, and Prior Recidivism

Movement data, codes that track all entries, transfers, and exits from Department facilities, were used to identify the inmate release cohort analyzed and whether inmates returned to prison. All movements (602,282) from July 1995 through June 2002 were collected for 127,858 inmates with at least one permanent release during the period. Excluding cases with movement data entry problems yielded 463,787 movement pairs (entry and exit from a facility).

Data on 608,773 offenses by these offenders, not committed while in prison, were analyzed to attach the first new offense, if any, to each prison release. Offense data came from a single source, consisting of all sentence components. This data includes all sentencing information, including offense dates, for every offense for which an offender was sentenced to the Department. These offense dates were used to measure the timing of recidivism.

Combining the movement and offense data yielded 244,777 releases for 127,689 inmates, of which 110,899 releases (97,825 inmates) occurred on or after July 1, 1995. The balance of 133,878 releases—before the cohort period—were used to measure prior recidivism events, a factor influencing recidivism.

Data on new offenses committed is not available until the inmate is actually readmitted to the Department (at which time the data entry is done) for incarceration or supervision. The delay between when an offense is committed and when new offense information becomes available in the Department's information system must be taken into account to prevent data collection timing from biasing results of the analysis.

Analysis of the distribution of time between new offense date and subsequent admission date indicates that 75 percent of offenders are received within 250 days. Inmate releases less than 250 days prior to data collection (March 5, 2002) for this report are not included in the analysis. Releases on or after June 28, 2001 were excluded from the analysis. Using this "buffer" period alleviates the problem of considering a released inmate a success (non-recidivist) when, in fact, he has not had sufficient time to return to the Department. Of the 110,899 releases (97,825 inmates) since July 1995, 106,167 releases (95.7%) for 96,415 inmates (98.6%) were retained.

Finally, 2,643 (2.8%) of the 106,167 releases were excluded because they involved death, release out of state or to another prison system, escape, or vacated sentence, leaving 103,524 releases for 94,272 inmates.

Other Inmate Characteristics

Data on inmate characteristics—other than prior recidivism—were obtained from a data file of all offenders ever in custody or under supervision with the Department. These characteristics include gender, age, race, and ethnicity. Demographic data were available for virtually all released inmates.

Criminal history data were obtained from movement and offense data files, primarily the latter. Offense data were used to measure multiple characteristics in four aspects of criminal behavior: density, geographic dispersion, diversity (offense type specialization), and severity (offense volume, type, degree). Measures of the onset and criminal career length and the prior recidivism characteristics were generated from combined movement and offense data. Movement data provided the prior supervision failure characteristics. No cohort cases were lost due to missing data on these characteristics. Some undercounting of criminal career characteristics may have occurred, but any undercounting is minimized because data elements used are required data entry fields in the Department's information system.

Movement data for offenders on supervision were used to identify inmates released to supervision. Prison movement data were used to measure time back in prison for technical violations of supervision conditions (time "not at risk" for recidivism).

Prison experience data were obtained from several source files. Length of stay was calculated as the time between prison admission and release, based on the prison movement data used to identify which prison releases qualified inmates for inclusion in the study. Custody level at release were collected from a series of inmate population status files, using the latest date prior to each release for each inmate in the cohort. Inmate behavior and special confinement history data came from files listing all disciplinary reports and movement data while in prison for each period of imprisonment.

Academic skill or achievement level was collected from special files that record scores—expressed as educational grade equivalents—on the Test for Adult Basic Education (TABE or TABM) for those inmates who took the test while in prison. The last test score prior to release was retained as an indication of the level of education attained prior to prison release. A substantial number of cases were excluded due to missing scores; however, this analysis retained 85.7% of the 103,524 remaining releases (94,272 inmates).

For more information about the final cohort analyzed for this report, see Release Cohort.


Historically, felony court dispositions show that 20% of offenders are sentenced to prison, 25% to jail, and 55% to supervision. Reoffenders sentenced to jail are not included in these estimated rates. To determine whether the absence of data on recidivists committed to jail lowers these rate estimates, the Department examined an alternate data source (sentencing guidelines forms). Analysis of that data shows that incorporating information on recidivists sentenced to jails does not affect the shape of the reoffense curve (i.e., the timing of recidivism). At most, including jail data would raise the reoffense rate estimates by an average of 1.2 points, with a maximum increase of 1.6 points in the 3-year range. This minimal effect reflects the low probability that former prison inmates are sentenced to jail instead of prison for subsequent felonies.

The U.S. Department of Justice Bureau of Justice Statistics reports that a substantial amount of recidivism occurs in states other than where prison inmates were released. However, this amounts to a small percentage of all state prison inmate recidivism. Within 3 years after release, only 3.7% of released prison inmates were only rearrested in another state. Given the ratio of reconvictions to rearrests in that study, it is reasonable to expect that no more than 2.6% of inmates released from Florida are reconvicted in other states. That percentage would increase these reoffense rate estimates by an average of .85 points, with a maximum of 1.3 points at 60 months. The Department has no access to data to allow such out of state convictions to be included in these recidivism rate estimates.

For more information on the data sources for this report, see the Technical Appendix.

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