The law enforcement industry is currently being served by a website called iHireLawEnforcement. Everything I have heard about this endeavor is positive. They maintain a database of job listings in the industry that users can access and apply to.
Additional Resources:
iHireLawEnforcement :: Listed on Incdatabase.com
iHireLawEnforcement :: Article on Inclistings.com
iHireLawEnforcement :: Information on Inc1000.com
iHireLawEnforcement :: Article on Professionaldatabaseinc.com
iHireLawEnforcement :: Listed on Thecorporatedatabase.com