You'll need to gain a bachelor's degree in the field of psychology. Choose a minor that will help you in the forensics field, such as criminal justice. Make sure your degree plan will culminate in a Bachelor of Science degree, which will be more useful than a Bachelor of Arts degree. Take courses such as criminology, criminal law and social psychology to lay a foundation for your career path.
Going to graduate school to earn a master's degree in Psychology will be your next step towards a career in forensic psychology. If you stop with this degree, you may end up working in an institutional-type facility or in a job involving more research-type work.
To get the most out of a career in forensic psychology, you must gain a doctoral degree to be a licensed psychologist. This degree will open up many opportunities in the field. You could evaluate offenders, be an expert witness for trials, open your own private psychology practice or work in a prison. The pay depends on which type of job you decide to pursue.