Christopher Youngkin: Texas: Bulletin; "One the state's top forensic experts responsible for blood testing in several DWI cases is under scrutiny for mixing up lab tests - and is also accused of making conflicting statements under oath."..."A hearing this week could affect many other DWI cases in seven counties since 2013. DWI Attorney Deandra Grant says last week’s hearing in Collin County was jaw dropping. A judge was so concerned about a state expert witness perjuring himself, the judge advised him to stop testifying. Christopher Youngkin is one of the leading forensic analysts for the Department of Public Safety." Fox4 News. (Thanks to Forensic Magazine for drawing this story to our attention; HL);

"One the state's top forensic experts responsible for blood testing in several DWI cases is under scrutiny for mixing up lab tests. He’s also accused of making conflicting statements under oath.
The swirling allegations of possible perjury stem from a current DWI case in Collin County. A hearing this week could affect many other DWI cases in seven counties since 2013. DWI Attorney Deandra Grant says last week’s hearing in Collin County was jaw dropping. A judge was so concerned about a state expert witness perjuring himself, the judge advised him to stop testifying. Christopher Youngkin is one of the leading forensic analysts for the Department of Public Safety. Court documents show he mixed up two blood alcohol tests on suspected DWI cases in 2013. Grant says Youngkin has testified multiple times about that incident and given conflicting accounts. ........Defense Attorney George Milner says his client, who did not want to be shown on camera, was recently acquitted in a DWI case where Youngkin admitted his 2013 error.   "The jury told me after the trial, they didn't believe anything he said,” Milner said. Grant and Milner question the validity of his blood tests and his testimony in other cases."
http://www.fox4news.com/news/212098707-story

See also: Dallas News story at the link below:  "Thousands of North Texas DWI convictions could be at risk after the testimony of a state forensic scientist whose work is key to such cases recently came under scrutiny. One defense attorney has described the issue as a "big mess," and the continuation of a hearing next week could clarify the lab expert's testimony and determine whether he faces any repercussions. In the cross hairs is Christopher Youngkin, who does blood alcohol testing for the Texas Department of Public Safety's crime lab in Garland and testifies about his findings in court. On Wednesday, he took the stand on a misdemeanor driving while intoxicated case in Collin County and ended up invoking his Fifth Amendment right not to testify. At issue is whether Youngkin may have given conflicting testimony under oath about a 2013 lab error in which he mixed up the results of two blood samples submitted by Anna police. A report Youngkin sent to police there showed a woman who had not been drinking had a blood alcohol level of nearly twice the legal limit. The error was discovered within days, the samples were retested and no one was harmed. The mix-up was deemed an isolated incident, according to a DPS report completed by Youngkin. But how that error has been handled since 2013 has caught the attention of local defense attorneys. They are looking into not only whether Youngkin may have given conflicting testimony about the mistake but also whether they should have been made aware of the 2013 lab error sooner."
//www.dallasnews.com/news/crime/2016/10/14/thousands-dwi-cases-potentially-risk-credibility-dps-lab-expert-questioned


See Grits for Breakfast story at the link below: "Thousands of DWI convictions in North Texas could be jeopardized after the testimony of a state forensic scientist recently came under scrutiny." Get used to these sort of headlines. In the coming years, many forensics historically admitted into evidence by courts will either be invalidated or, even where the science is valid, performed by incompetent analysts using unjustifiable methods. The temptation to treat them each as isolated incidents should be ignored. In many cases, folks are looking skeptically at long-used forensics for the first time to assess their validity, and more often than not, what they discover isn't up to snuff."
 http://gritsforbreakfast.blogspot.ca/2016/10/forensic-snafus-depressed-das-and.html

See CSIDDS (Forensics in Focus) post - 'A real bad day...Judge tells Texas state forensic examiner to stop testifying in DWI case' - at the link below; "
 https://csidds.com/2016/10/18/a-real-bad-day-judge-tells-texas-state-forensic-examiner-to-stop-testifying-in-dwi-case/