Final answer:
A person whose criminal activity starts in early adolescence and persists through life is termed a 'Habitual offender.' This relates to ongoing debates in the criminal justice system about the effectiveness of juvenile incarceration and rehabilitation.
Step-by-step explanation:
The term used to describe a person whose criminal activity typically begins in early adolescence and continues throughout life is Habitual offender. This term denotes individuals who repeatedly engage in criminal behavior and are frequently involved with the criminal justice system. The difficulty with juvenile offenders is that they often continue their life of crime into adulthood. In the context of the criminal justice system, there are debates about the effectiveness of juvenile incarceration and alternative methods of rehabilitation. Incarceration is believed by some to increase the likelihood of recidivism, and alternative solutions like community service are suggested to be more beneficial. Labeling theory in sociology also plays a significant role as it suggests that labeling individuals as criminals may reinforce criminal identity and behavior, leading to a cycle of crime.