The Holmes Middle School teacher, whom students identify as Sgt. Griffin, teaches a leadership course. The recording in question was documented by a 6th grade student recording with a cell phone under a table.
In the recording, the teacher can be heard saying, "Those of you that know me, you know I'll go as far as you want me to go. So if you wanna act a fool with me, guess what? If you got no filter, then I ain't got no filter. If you got no threshold for pain, then I don't either. If you don't give a f---, I don't give a f---."
He also talks about a test using explicit language, and later is heard saying that he's not trying to be vulgar.
"On Thursday, you guys are going to have a test over this material and you've got to be able to pass it," the teacher says. "Now most of y'all f----- up that last test up, and I'm going to tell you the truth: y'all f----- it up. It took your grade down by five to 10 points."
The mother of the student who recorded the teacher took the recording to the school on Tuesday and refused to leave until the principal listened to it.
Dallas ISD released a statement confirming the teacher has been placed on leave while it investigates.