Prosecutors spent all day trying to convict someone, at least in part, with the HPD BAT evidence. It's the DA's plan to try to prove that this stuff is and was scientifically sound.
On Monday, Harris County District Attorney Pat Lykos told us she had problems with the way HPD handled BAT van DWI testing.
"Do you trust the results coming out of the BAT vans?" we asked Lykos.
"I want the Texas Department of Public Safety to supervise the technicians so that we can be assured that everything is done according to protocol," she replied.
But on Wednesday, her assistants were in court trying to convict an alleged drunk driver relying at least in part on HPD BAT van evidence.
"There's no reason for the DA to think that this case is reliable," defense attorney Jacquelyn Carpenter said.
Carpenter says the DA should keep the BAT vans out of court until the controversy is settled, but the DA seems to say it is.
On Wednesday, the DPS technician supervising HPD's breath tests told a jury he studied the HPD machines and couldn't find the problem critics say exists.
Defense lawyers say that's not enough.
"DPS is saying that now, over the course of the last five months, this is a test from before DPS got involved when it was still within the compounds of HPD," Carpenter said.
Meanwhile, the grand jury looking into who knew what and when about bad BAT vans is still working. On Wednesday, the grand jury added two former assistant DA's to their team as special independent prosecutors.
We still don't know if their target is HPD or the DA's office. But the judge who appointed the special prosecutors called the grand jury investigation "a case in which grand jury intends to investigate possible criminal conduct by a district attorney or members of her office."
"Do you believe your office is being investigated by this grand jury?" we asked Lykos earlier this week.
"I don't think so," she said.
"Have you done anything wrong?"
"Of course not."
Those grand jurors will be the ones to decide that. They're now being aided by two former but experienced prosecutors who used to work for the DA's office. The jury is expected to meet in secret again on Thursday.