Beyond the obvious choice of working in a government crime lab, there is a growing demand for forensic science professionals in the homeland security and national intelligence communities.  These analysts are needed with the same core scientific skills as traditional crime labs, except that their analysis is used for homeland security and related activities rather than criminal prosecutions. 

Also recognize the potential for crossing over to closely related disciplines.  A forensic scientist with a biology or chemistry concentration is also prepared to work in environmental science, since many environmental investigations have the potential for criminal prosecution or civil litigation.  Likewise, a forensic science degree is an unparalleled background for graduate school in law, medicine, biology, or chemistry.

Forensic Science laboratory work is most often performed in government crime labs by well-trained scientists who may or may not be sworn law enforcement officers (depending on department).  Ideal preparation is a B.S. in Forensic Science, Biology, or Chemistry.  Specific areas are described in this link.