Vantaggi
If you are in your early 20s, there are lot of people who are in your age range and a good mix of educational backgrounds. A good place to start off your career and to build up useful experience which you can use to apply for jobs at other HR companies or at careers related to criminology, IT or management depending on which department you are working.
Svantaggi
The company hires people who have just completed a degree. They don't pay much to start because they know that you need to get a job right away to start paying back loans, etc. So while it is good that the company is hiring new grads, the pay scale is a bit poor. Depending on where you are, there are only limited opportunities to get raises. This isn't a company you would work for longer than 5 years unless you somehow got into management.