It’s a long-standing debate: Do juvenile offenders become worse because of their experience with the justice system, or are they somehow different than people who don’t have their first criminal conviction until later in life?

“There seems to be a lot of evidence that people who are convicted early are more heavily involved in crime,” said Amber Beckley, Ph.D., a postdoctoral researcher at Duke University.

Using data from a study that tracked nearly 1,000 New Zealanders from birth to age 38, Beckley looked at patterns that would distinguish youthful offenders from what she calls “adult-onset offenders.”

Of the 931 study participants, 138 males began their criminal activity as juveniles. The adult-onset group consisted of 66 males.

Of all the participants, 42 percent of the men had some sort of conviction, ranging from shoplifting and DUI to property crimes and assaults, according to the researcher.

Because of the rich data set, researchers were able to look at childhood history compared with adult behavior.

What they found is that the adult-onset group had a history of antisocial behavior back to childhood, but committed fewer crimes than people who had been in trouble as juveniles.

They also discovered that adult-onset offenders were more likely than non-offenders to have schizophrenia or bipolar disorder and to be dependent on alcohol, but they were no more likely to be unemployed.

Beckley said the findings have clear implications for the mental health component of adult-onset criminal behavior.

“It should be addressed in sentencing, because it’s not now and most incarcerations aren’t exactly therapeutic,” she said.

“I don’t think the court system has a large role in the juvenile offender’s trajectory,” Beckley added, noting the New Zealand juvenile offenders reported that they were doing more and worse crimes at a young age, “before they even got caught.”

If there were any recommendations out of this study, Beckley said hers would be to focus more on juvenile offenders while perhaps being a bit more lenient on first-time adult offenders.

“We should continue to devote resources to juvenile justice because two-thirds of the criminal population first commit crimes in adolescence,” she concluded.

The study was published in the Journal of Criminal Justice.

Source: Duke University