Charles Hess Investigations
- Full service detective agency servicing Maryland and the United States. Provides confidential and professional investigations for individuals, law firms, insurance companies, private organizations and corporations.
- http://www.marylanddetectives.com/

Absolute Investigative Services
- Baltimore-based firm offering professional investigators, private detectives, and security guards. Background and full list of services available.
- http://www.absoluteinvestigativeservicesinc.com/