"She picked it up and didn't think anything of it, but as she drove to her destination she began feeling a little bit lightheaded and having a few other symptoms," said Sheriff Ed Gonzalez.
So who distributed these flyers, and why?
It appears the origin of the flyers came from Targetedjustice.com, a website that delves into conspiracy theories and claims that the government is targeting and controlling individuals psychologically through microwave beams.
One link on the website even allows anyone to download the same exact flyer that was found all over the deputy vehicles.
URGENT: Flyers placed on the windshields of some #HCSO vehicles this afternoon at 601 Lockwood have tested positive for the opiod Fentanyl. One sergeant who touched a flyer is receiving medical treatment. Call authorities if you see these flyers and DO NOT TOUCH. #hounews #lesm pic.twitter.com/1mp03U8OGn— HCSOTexas (@HCSOTexas) June 26, 2018
The tough part for investigators is that it could have been anyone who printed and passed out these flyers. The only clues on the flyers themselves may be fingerprints.
"Someone could have died. The fact it is now being used against officers is a game-changer," said Harris Co. Pct. 1 Constable Alan Rosen.
Constable Rosen and several other local law enforcement agencies are trying to stay on top of the game by arming officers with Narcan, an emergency treatment used for opioid overdoses.
"We want to arm our officers with Narcan so it can be there in the event that they get accidentally exposed. This is just part of what an officer has to encounter these days," added Rosen.
The encounter with Fentanyl can be deadly even if found on a flyer and absorbed through the skin.
"They can soak it. There's a lot of different ways, but mainly soaking it and this is purposely -- obviously purposely -- done with the intent to harm police officers. So it really is hitting us in our own backyard. I can tell you this case will be vigorously investigated and we will hopefully catch the people that did this. I mean, this is a very serious matter," said Rosen.
Follow Chauncy Glover on Facebook and Twitter.