In prisons, however, approximately 60 percent of adults have had at least one TBI—and even higher prevalence has been reported in some systems. These injuries, which can alter behavior, emotion and impulse control, can keep prisoners behind bars longer and increases the odds they will end up there again. Although the majority of people who suffer a TBI will not end up in the criminal justice system, each one who does costs states an average of $29,000 a year.