AMES, Iowa – A life sentence in many states rarely means offenders will spend a lifetime behind bars. In fact, offenders sentenced for murder served just 15 years on average before initial release from state prison, according to a recent Bureau of Justice Statistics report using national-level data.

While the report did not look at recidivism, Matt DeLisi, the College of Liberal Arts and Sciences Dean’s Professor in the department of sociology at Iowa State University, says there is a strong likelihood offenders convicted of a violent crime or other serious felonies will commit the same crime again. In a new study, DeLisi and his colleagues examined data for serious offenders committed to the California Youth Authority (now the Division of Juvenile Justice) between 1997 and 1999, and found a prior conviction significantly increased the likelihood for the same offense by the following percentages:

Homicide: 1,467 percent

Robbery: 294 percent

Aggravated assault: 200 percent

Burglary: 148 percent

Drug sales: 736 percent

The findings, published in the journal Youth Violence and Juvenile Justice, illustrate the need to consider an offender’s entire criminal history during sentencing or when considering parole, DeLisi said. This is especially important as Congress considers legislation to reduce federal sentencing guidelines, he added.

“For many offenders, their behavioral histories do not support releasing them. Consider a 40- or 50-year-old offender in prison for drug trafficking with a criminal history of armed robbery, rape or murder. Right now, he may be a drug offender based on the current offense, but if he has a history of committing a range of more serious offenses, why wouldn’t he do it again?”

Convictions for what DeLisi calls “extraordinary risk crimes” – murder, kidnapping, rape, armed robbery – are signals an offender is extremely antisocial. DeLisi says these are typically lifelong offenders, many with pronounced antisocial personality features. Conditions such as monitored sobriety, no-contact orders or home visits assigned as part of parole are unlikely to change their behavior.

Andrew Hochstetler, professor of sociology; Mark Heirigs and Jacob Erickson, both graduate students in sociology; and Ramate Bunga, former criminal justice student, all contributed to this research.

Link between psychopathy and homicide

Psychopathy is one possible explanation for the high rate of recidivism, particularly for homicide. The prevalence of psychopathy in the U.S. is relatively small, only around 1 percent, but researchers say it is significantly higher among prison populations.

In a separate study, DeLisi and Bryanna Fox, lead author, former special agent with the Federal Bureau of Investigation and assistant professor at the University of South Florida, identified a strong link between psychopathy and homicide. While there is a cultural notion that murderers are psychopathic, DeLisi says this is the first meta-analysis to look at both issues.

The review of 22 studies, including approximately 2,600 homicide offenders, found the average psychopathy score was 21.2, which is considered moderate psychopathy on a scale of zero to 40. Most people in the general population score zero on this measure.

DeLisi says there was a strong correlation, which was even stronger for sexual, serial and multiple offender homicides. In other words, the more pathological the type of homicide, the stronger the association with psychopathy. The work is published in the journal Aggression and Violent Behavior.

Psychopathy is broadly defined by characteristics such as lack of remorse and empathy for others, self-centeredness, pathological lying and little consideration for the consequences of various actions. From a very early age, DeLisi says psychopaths exhibit severe conduct problems that are noteworthy for their level of violence and chronicity. Psychopaths do not accept responsibility for their behavior and often see the victim as a means to some end, he said.

“I’ve interviewed offenders who have committed homicides, and one of the chilling things about these offenders is they explain or describe it in very matter of fact, calm terms. They have no emotional connection to their victim or sense of guilt or shame for what they have done. They just describe it like they’re doing yard work or preparing dinner,” DeLisi said.

In 2013, DeLisi testified before the U.S. Senate Judiciary Committee that cutting prison sentences would put more offenders back on the streets and increase the crime rate. He says this meta-analysis provides additional evidence of why criminal history must be considered as Congress weighs changes to sentencing guidelines.