A forensic toxicologist at the lab who tested George Floyd's blood said it was common for drunk driving suspects who consumed fentanyl for have higher levels of the drug in their systems than Mr. Floyd did when he died. Prosecutors hoped his testimony would deal a blow to Derek Chauvin's attorney's argument that Mr. Floyd may have been overdosing.
Toxicologist Dr. Daniel Isenschmid works at NMS Labs in Pennsylvania and testified on the ninth day of the trial against Mr. Chauvin, who was charged with murder in the death of Mr. Floyd. On more than 2,300 samples of blood from drunk drivers, the NMS Labs tested last year - all of which were in cases where the driver survived and tested positive for fentanyl - about a quarter of people had levels of fentanyl equal to or greater than that of Mr Floyd, Dr Isenschmid said.
Prosecutors had called him to the stand to rebut the argument Mr. Chauvin's lawyer that fentanyl, a strong opioid, caused Mr. Floyd's illness. overdose. Prosecutors say Mr. Chauvin was responsible for Mr. Floyd's death, and earlier on Thursday , a pulmonologist said that Mr. Chauvin's knees on Mr. Floyd's neck and back were major factors in his death .
Dr. Isenschmid said that last year in cases where N.M.S. The labs tested the blood of a deceased person who had taken fentanyl, the average amount the scientists found was 16.8 nanograms per milliliter, about 50% higher than the amount found in M's blood. Floyd. But Mr. Chauvin's attorney, Eric J. Nelson, noted that the average was among people who died from any cause and had fentanyl in their system, not just overdoses. And, he pointed out, the median fentanyl level in that group was slightly lower than Mr. Floyd's.
The testimony of Dr Isenschmid, who previously worked as a toxicologist inchief at the Wayne County medical examiner's office in Detroit, was one of the more technical yet, but jurors seemed attentive, according to a reporter in the courtroom.
He said that when a person 's body processes fentanyl, it turns into norfentanyl, and that Mr. Floyd has a relatively high proportion of norfentanyl, which indicates that her body had already processed a substantial portion of fentanyl. This reinforced prosecutors' argument that Mr. Floyd had not overdosed; Fentanyl overdoses often happen soon after taking the medicine, before a person's body can break down much of the medicine.
But Dr Isenschmid conceded, in response to Mr Nelson, that it was also possible that Mr Floyd had taken and treated fentanyl earlier during the day, then consumed more in the momentsbefore or during the arrest. The toxicology results, Dr Isenschmid said, do not indicate when a specific amount of fentanyl was taken.
Mr. Nelson pointed out that the pills that had the D.N.A. of Mr. Floyd on them and may have been partially ingested were found in the back of the police car in which Mr. Floyd was briefly placed.
Still, Dr Isenschmid stated that the same amount of fentanyl can have very different effects in a new user compared to someone who is drug dependent. Mr. Floyd 's girlfriend said that she and Mr. Floyd both had difficulty stopping opioid use .
"If a person becomes tolerant of un drug, she needs more and more to achieve the desired effect "said Dr Isenschmid.
Methamphetamine has also been found in Mr Floyd's system, although Dr Isenschmid said the levels were so low that they probably had no intoxicating effect.