A Harris County prosecutor went before a grand jury Thursday and refused to answer their questions, but special prosecutors have asked a judge to force her to testify.

That grand jury is investigating alleged prosecutor misconduct in connection with questionable DWI results.

Rachel Palmer is a division supervisor in the Harris County District Attorney's Office misdemeanor section. She oversees hundreds of drunken driving cases each year.

Palmer was called before the grand jury that is investigating the alleged cover-up of problems with DWI tests performed by the Houston Police Department's breath alcohol testing vans.

Questions about the accuracy of driving while intoxicated tests performed by the vans were raised by a former HPD lab supervisor earlier this year. In October, a grand jury began investigating to determine if prosecutors knew the test data they were using to prosecute accused drunken drivers might be flawed.

"It would be a question of what she knew and when she knew about the reliability of the evidence that the BAT vans were producing," KPRC Local 2 legal analyst Brian Wice said.

Palmer refused to testify, reportedly citing Fifth Amendment protections against self incrimination.

Special prosecutors immediately hauled her up to Judge Susan Brown's courtroom and asked that she be forced to testify.

"God is good," Palmer said. "I'm not worried about a thing. It's a great day."

During the hearing, attorneys revealed that Palmer is not a target of the investigation  -- one of the reasons prosecutors contend she should be compelled to testify.

Brown heard arguments from both sides, but she did not make a ruling in order to give Palmer's attorneys more time to research the law.

Palmer's boss, First Assistant District Attorney Jim Litner, reacted angrily to suggestions that it is improper for her to refuse to testify.

"Someone took the fifth. The law says they can," Litner said. "You want to make something look bad about it. There's nothing I can say about it. The policies are everybody follows the law, that's it."

Both sides will return to court Monday. That is when Brown will decide if Palmer will have to answer the grand jury's questions.