Commonwealth v. Read — Trial Archive Expert Witness · MA Toxicology Lab
Nicholas Roberts
Trial 1 137 lines of testimony
Nicholas Roberts, a forensic toxicologist with the Massachusetts Toxicology Lab, testified exclusively in Trial 1 on Day 18. His role was to convert Karen Read's hospital serum alcohol level—drawn at 9:08 a.m. on January 29, 2022—into a whole blood BAC and then extrapolate backward to estimate her BAC at 12:45 a.m., the time prosecutors identified as her last drink. His calculations placed Read's BAC at that earlier time somewhere between 0.135 and 0.292 g percent, a range the prosecution offered as evidence that Read was significantly impaired when she dropped off John O'Keefe.