when becoming a probation officer can you choose to work with younger people?

Yes, you can certainly choose to work with juvenile offenders. State or county systems typically have a designated group of juvenile probation officers. In the federal system there is not a designated juvenile section as we do not have that many.

Any probation officer has a dual role of enforcing the judgment of the court (protect the community) and also assisting the offender. Many times if you assist the offender you are achieving success in both roles. If you act as a role model for juvenile offenders you are modeling pro-social behavior that they can then use themselves so that they don't come back to the probation system.

Working with juvenile (and adult) offenders is quite demanding but also very rewarding. You have the opportunity to make a true difference in the life of the individual that you supervise as well as the community.