The message also warned her that if they filed charges against the drug dealer she bought from, she would be named in the affidavit as a source, revealing her as the person who "snitched" to the police.
The Chief of Police texted her attorney, telling him that by withdrawing from the deal, she "acknowledges that we may file a charge in the case of the controlled buy that she made and that she could be named in an arrest warrant."
In a phone conversation with Police Chief Bob Wieners, recorded by one of the woman's attorneys, the chief reiterated that "threat," KTRK reports.
"We can go ahead and just file a warrant, based on the one controlled buy that she did, and name her in the warrant," Wieners said, according to KTRK.
The detective said in his text message any charges would be decided by the Brazoria County District Attorney's office, but that DA's office told ABC News the arrest didn't happen in their jurisdiction.
The arrest happened in Galveston County, according to Johnson, but that DA's office told ABC they don't deal with traffic violations.
"Nobody in the legal community in our area knew anything about this so-called program the police department was running," Johnson told ABC. "We've never heard of anything like this before."
The woman's attorney said they are fighting the two traffic tickets, but have not yet decided whether to take legal action against the police department.