A long time. Most likely you would need a degree in psychology or a related field (four to five years). Then you would need to gain employment with a large law enforcement agency and gain years of experience.
In the United States, criminal profilers would usually need a degree in behavioural and/or forensic sciences. A double major would be useful, and the time to complete a degree in these areas may vary depending on which faculty or degree you decide to complete and how far you want to go in that area (i.e. degree, masters, ph.d.). These degrees alone will not necessarily make you eligible to do profiling work. Australia has a similar approach. Both countries usually have profiling work done within law enforcement agencies, and so working within law enforcement for a period of time would probably be of the most benefit. In the United Kingdom, profiling work is usually based on investigative work by psychologists. Despite where you live, finding work in a field where you would be called upon to conduct "criminal profiling" is competitive.
See related link below for the FBIs requirements for working in the NCAVC.
5-7 years
You would have to be in college for about 6 years to become an astronomer.
You can become a magician without college
To become a counselor, you need four years of college (a Bachelors Degree). To become a licensed therapist, you need to obtain a Masters degree (5-7 years of college).
You need 7 years of college.
4 years
you need to go to college for 2 years
you have to go to college for about 5-7 years
how many years in college does it take to become a diagnostic radiologist noninvasive?
You would have attend about 6 years of college before you can become a Astronomer.
Eight years in college
5 years
At least six years