My Future

I know exactly what I want to do in life. I want to be a criminologist. I need a four-year bachelor's degree in Psychology and a two-year degree in Criminal Justice as well as training. If you are in the U.S. you most likely know about Stanford University. This is the school where I want to study psychology. The acceptance rate is around 4.3%. I am wondering if taking dual-enrollment classes is a good idea to help me in the long run. All my high school classes are already honors.

It's brilliant that you have a solid idea about what you would like to do as a career and that you have already taken steps to ascertain what is needed for this job. I imagine my dual-enrollment you mean that you will be taking higher difficulty (college level) courses whilst below the normal age of sitting said courses.
As someone who has done this in the past of my academic journey to university, I would say this is a brilliant idea to push yourself forward and set you apart from other applicants however this might also be a lot of pressure to put on yourself. Of course you would know yourself and your abilities better than anyone else so if you feel that this is something you can take on that won't compromise your current studies then by all means go ahead. I would suggest that you are averaging A's at the least to take on a course at a higher level than your currently studying at. If you are slightly lower than this then you can still do a dual enrollment if you really like but be aware of how risky it is and how much effort you have to put in in the coming years to ensure you don't fall below.
Hope this helps at all