| Business | Phone |
| Accord Detective Agency 1420 Renaissance Dr, Park Ridge 60068 | (847) 456-3512 |
| Argus Agency 1480 Renaissance Dr, Park Ridge 60068 | (847) 297-4422 |
| Elite Investigations Inc 1580 N Northwest Hwy 117, Park Ridge 60068 | (847) 803-1502 |
| Chicago Loss Prevention Group 100 Higgins Rd 204, Park Ridge 60068 | (847) 825-1940 |