The investigation by the Tennessee Bureau of Investigation appears to be basic due diligence, perhaps. Apparently someone was concerned that the CCTV cameras in the Nashville District Attorney, Glenn Funk’s office might be recording a little too much audio.

To ensure nothing nefarious was going on, TBI brought in their TSCM team to help verify that no illicit eavesdropping was occurring.
The Channel 5 TV News team “just happened” to be on the scene and was able to record video of the TBI team going about their work.
Pelican cases, ladders, tools, and a number of technicians were spotted working around the DA’s office.

Watch on YouTube:

There are a couple of important considerations here –
1. If you have security cameras installed, AND if they record audio- you may be a target for law suits, whether or not you believe you are obeying the law. Check your cameras and to be safe, do not record any audio.
2. How did the TV news team know about the sweep? Likely someone leaked the information to them… how well do you train your employees to respect confidential information and how loyal are they?
You most likely do not want a news team show up at any of your TSCM inspections.

You can read more about the incident here:
https://www.newschannel5.com/news/newschannel-5-investigates/the-das-deals/listening-devices-installed-around-nashville-das-office-installer-confirms-da-defends-practice