Judge warned DWI expert to stop talking, get a lawyer, after conflicting testimony

Here's more detail from the Dallas News on a North Texas forensic mess that Grits earlier referenced in a roundup:

A state forensic scientist whose work has been called into question will no longer serve as an expert witness or perform lab work in drunken driving cases in Dallas, Collin, Denton and Rockwall counties. 

At the request of court officials in those counties, cases pending trial that were worked by Chris Youngkin will be reanalyzed by another DPS forensic scientist, according to a statement from the Texas Department of Public Safety.

Benching Youngkin doesn't eliminate the problem, though, because he is still part of the chain of custody for blood samples collected in thousands of DWI cases.

The analyst's "credibility came into question over a 2013 lab error that showed a driver who had not been drinking had a blood alcohol level of 0.152," and he "has given conflicting testimony about that error in different trials in different counties." The News had earlier reported on a dramatic court hearing where the analyst's conflicting testimony surfaced:

According to a partial transcript of Wednesday's hearing, defense attorney Troy Burleson questioned Youngkin about a Dallas County case in which he testified he switched vials in 2013. Burleson then asked about Youngkin's testimony in the Collin County case in which he stated that he had never switched vials.

"We have two inconsistent statements that cannot both be true," Burleson's law partner, Hunter Biederman, said after the hearing.

County Court at Law Judge Lance S. Baxter advised Youngkin during the hearing that he had the right to remain silent and the right to consult an attorney. When Youngkin invoked his right not to testify, the hearing came to an end.