The primary qualification that you need to get a probation officer internship includes enrollment in an undergraduate program with a major in criminal justice or criminology. Some programs accept students in social work or legal studies bachelor's degree programs as well. Students seeking a probation officer internship needs to be able to take direction from a probation officer or another supervising administrator, perform research online and through books and other hard copy, and communicate with both the clients sentenced to probation as well as law enforcement and social service professionals. Internships can last for one school term (a semester or a quarter) or an entire school year.