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Rick Scott, Governor
Florida Department of Corrections, Secretary Michael D. Crews

Florida Department of Corrections
Timothy H. Cannon, Interim Secretary

Methodology

Only inmates released from Florida prisons from January 1, 2004 to December 31, 2011 are included in the study with the following exceptions:

  • Inmates who died or were executed have been omitted from the calculation of recidivism rates.
  • Inmates who are missing information on the factors of interest are omitted.
  • Inmates with more than one release in a calendar year have only the first such release included.
  • Inmates with detainers in place at the time of release are omitted.

This methodology follows the Association of State Correctional Administrators (ASCA) Performance-Based Measures System counting rules definition of recidivism. As a result of consulting with the National Institute of Corrections' Patricia Hardyman, Ph.D., additional variables were added to the study this year: 

  • Placing a time restriction (five years) on how long prior to the admission date to count non-violent offenses,
  • Placing a time restriction (fifteen years) on how long prior to the admission date to count violent offenses,
  • Suspected or confirmed gang involvement, and
  • Age at first offense.

For this study, survival analysis techniques are used to compute recidivism rates and to define the statistical models used to determine which factors significantly influence recidivism rates. The basic rates for tables and graphs are computed from Kaplan-Meier estimates of the survival curve using right-censored data. The analyses of factor significance are conducted using Cox models (proportional hazards regression) of the same data. The analysis used a 5% level of significance to determine the factors in order of importance, and a stepwise selection routine for determining which factors to include. The correlations between factors were considered during the stepwise routine to eliminate highly correlated variables from both being selected for inclusion in the model. In those cases, the first variable selected was included and the correlated variable was eliminated from consideration.

The following variables were considered for inclusion in the model:

  • Gender is Male – Yes/No
  • Number of Prior Prison Commitments
  • Age at Release
  • Age at First Offense
  • Confirmed Gang Member – Yes/No
  • Confirmed or Suspected Gang Member – Yes/No
  • Number of Disciplinary Reports in Current Incarceration
  • Most Recent Tests of Adult Basic Education (TABE) score (education level in grade equivalents)
  • Time Served in Prison, Current Incarceration in Months
  • Worst Offense is Murder/Manslaughter – Yes/No
  • Worst Offense is Murder/Manslaughter within 15 Years of Admission – Yes/No
  • Worst Offense is Sex Offense – Yes/No
  • Worst Offense is Sex Offense within 15 Years of Admission – Yes/No
  • Worst Offense is Robbery – Yes/No
  • Worst Offense is Robbery within 15 Years of Admission– Yes/No
  • Worst Offense is Other Violent Offense like Assault or Kidnapping – Yes/No
  • Worst Offense is Other Violent Offense within 15 Years of Admission – Yes/No
  • Race is Black – Yes/No
  • Ethnicity is Hispanic – Yes/No
  • Supervision to Follow Prison – Yes/No
  • Low Custody (Minimum or Community Custody) – Yes/No
  • High Custody (Close Custody) – Yes/No
  • Number of Burglary offenses in criminal history
  • Number of Drug offenses in criminal history
  • Number of Theft/Fraud offenses in criminal history
  • Number of Weapons offenses in criminal history
  • Number of Burglary offenses within 5 Years of Admission
  • Number of Drug offenses within 5 Years of Admission
  • Number of Theft/Fraud offenses within 5 Years of Admission
  • Number of Weapons offenses within 5 Years of Admission
  • Diagnosed Mental Illness – Yes/No
  • Substance Abuse Severity Score
  • Inmate-Reported Drug Screening Score
  • Inmate Concerned about Child’s Welfare – Yes/No
  • Inmate Extremely Concerned about Child’s Welfare – Yes/No
  • Inmate has No Enemies – Yes/No
  • Inmate has Enemies – Yes/No
  • Inmate’s Family is in Crisis – Yes/No
  • Inmate’s Family has a Negative Influence on the Inmate – Yes/No
  • Inmate’s Family has a Positive Influence on the Inmate – Yes/No
  • Inmate’s Friends have a Negative Influence on the Inmate – Yes/No
  • Inmate’s Friends have a Positive Influence on the Inmate – Yes/No
  • Inmate’s Spouse has a Negative Influence on the Inmate – Yes/No
  • Inmate’s Spouse has a Positive Influence on the Inmate – Yes/No
  • Inmate has No Spouse – Yes/No
  • Inmate has a Negative Relationship with their Attorney – Yes/No
  • Inmate has a Positive Relationship with their Attorney – Yes/No
  • Inmate has other Negative Influences in their Life – Yes/No
  • Inmate has other Positive Influences in their Life – Yes/No

It should be noted that for the "Worst" Offense factors the hierarchy is Murder, Sex Offense, Robbery, and Other Violent Offense. Each inmate can only be designated in at most one of the categories.  For example, if he has committed both sex offenses and robbery, he will be considered in the "Worst Offense is Sex Offense" category, not in the "Worst Offense is Robbery" category.

Also, for the criminal history factors, only those offenses for which the inmate received either a Florida prison sentence or Florida community supervision sentence are considered. Crimes in Florida that resulted in other sanctions, such as fines or county jail or federal sentences, are not considered.  Arrests, supervision, or prison sentences outside of Florida are not considered unless they are part of the inmate's Florida sentence.