Most people in law enforcement, criminal justice, corrections and the legal fields are here for a life-time. Many do 20 or more years, depending on if they promote upwards and obtain ranks, degrees, and different positions within their careers. Many go on to teach on the side and do that for 20 or more years. It took me almost 18 years to get into my field (from high school until I got my job at the Sheriff's Office). Fifteen of those years were after getting my Bachelor's degree. It just depends on you, how much you love what you are doing or where you want to be. Retirement is the goal, but not the end.
Best of luck to you and I hope you find a career you love.
Anthony Sharp - The Edutainer (HE He/Him/His)
It depends on the concentration that you want to go into. With regard to Criminal Justice, it usually will take 2-3 years to complete your education. You can usually enter your career in the field depending on the specialty. Law Enforcement, Border Patrol, Probation careers usually begin after high school. Many people go to college to obtain a degree for a higher starting pay.
Hope that helps.