Hard-science graduate degrees in forensics
By far, most hard-science graduate degrees in forensic science are not called "forensic science" at all. Instead, if you want to do forensics, the schools encourage you to get a degree in chemistry, biology or biochemistry, and focus your coursework with some electives in forensic science. Without a doubt, these science courses can be hard as hell (if you don't know the difficulty difference between a course in Cell Biology and a course in Crime Studies, you will quickly learn).
There are, however, about six fully-accredited M.S. programs in Forensic Science in the United States. These are programs that teach the hard sciences to the extent that a pure-science degree would, but take a hands-on approach to ensuring that you have a well-crafted, planned approach to your training. They sometimes grant an M.S. in Forensic Science, and sometimes grant an M.S.F.S (Master of Science in Forensic Science). In fact, many graduates with an M.S. in Forensic Science who will put "M.S.F.S" after their name, to signify that their Forensic Science degree is, in fact, a hard-science degree.
The difference here may seem trivial, but it serves the important function of distinguishing graduates from criminal justice programs from hard-science programs. It ensures that others can adequately gauge the experience and training of the forensic practitioner on a quick glance.
Advice for future Forensic Scientists
If you want to work in crime scene investigation, and can do science, then get a B.S. or M.S. in forensic science or a pure science. Your options will be so much better. If you get a B.S. or M.S. in forensic science, you will have enough criminal justice-type courses under your belt to work anywhere. If you get a B.S. or M.S. in a pure science only (like chem or bio), then be sure to supplement your work with courses in the Criminal Justice Department.
If you get a B.A. or M.A. in criminal justice, it is just not really possible because of time constraints to get enough courses in hard sciences to learn the science side of things. Even if you managed to, somehow, there's really no way to illustrate this to a jury in a convincing manner, in such a way that demonstrates your mastery of the science to which you are testifying. I would not want to be the prosecutor putting on the stand my forensic scientist who analyzed the blood for DNA, who has a degree in criminal psychology with 18 hours of classes in biology.