Looking into a couple of options for who the security agency might be that Pinkerton works with in the Colorado area that supposedly hired Matt Dolloff.

I started off by getting creepy on LinkedIn....

Here we have Chris Morton, the Director of Key Accounts (Global & National) at Pinkerton. He is located in the Greater Denver area. He has been in the role for 8.5 years.

Chris both shares posts from and "likes" Securitas Security.

Securitas does have a Denver office, and they offer security officer services. It also lists Pinkerton as an affiliate.

Website:
https://www.securitasinc.com/ 

He also "likes" Precision Security Team LLC. It is located in Fort Collins Colorado, but the site specifically says it served the Denver Metro area. And they offer off-site protection.

Website:
https://precisionsecurityteam.com/ 

Going back to Securitas, on Indeed they have listings for "Security Flex Officers" in the area.

https://www.indeed.com/viewjob?jk=8d5633539b40d5a5&tk=1ekg054usu2ve800&from=serp&vjs=3&advn=3136151319590847&adid=360100380&ad=-6NYlbfkN0DGgn67KApSZewFxdgJk0gQ3gGqzmsOotxt0L2xAZIOVag0laLEo1za8tDmb5iyLgVL7TSOvgeldaQxclakF5SQNKkP-LJWV4R0mA0NpEgGKtyJmVDQHXYkWLyjVcVA82WwqHp9MqY1QOqTcyjdYB7jQg-kk9lKYKEtX0LqyGFd92yFLZdUIjiOUSBRnMbQQNzXGMSHiohh390uArDDjt6ylGn9w7PSslqjoKXbTEdwRGvUmpyvIGuw0sk4MAUrKgTiRNJilPxMnDuGPTBi-3Fnif28qwY7LBCa2lzIXy13T9sSeNnvmwyzDC0tjRFJRevguKUJyMktHQ==&sjdu=vUz3PJIdpGfygLQXVlxEDlTSukTfYKA2eCJ7BKLAHXOQgnR8cajzaevNa6Fb9Q7mkjqe1ju01rXvGHOpZsrRqCxVunG9s3ttVCfqRtfzC0ZCTzrCM8-kB5BPY-8T--_rHPTlmR0m19txDh27doLyzw

Pinkerton also has part-time agent jobs listed, but I don't think this is what we are looking for.

Will keep adding onto this thread if new things come up during my digging time. :)
https://www.indeed.com/viewjob?jk=0dec7f897497c840&tk=1ekg0acb0t58k801&from=serp&vjs=3