Forensic scientist reveals untested blood evidence in Karen Read's trial for her boyfriend's murder.

A forensic scientist testified in Karen Read's murder trial that blood evidence collected in red Solo cups at the crime scene was never tested. The evidence included broken glass and scratches on Read's SUV, but it remains unclear if the samples still exist. The trial focuses on whether Read intentionally struck her boyfriend, Boston police officer John O'Keefe, with her SUV, leaving him to die in a snowstorm. Read's defense argues she was framed in a police conspiracy. The prosecution's case has spanned nearly four weeks, with key witnesses including O'Keefe's 14-year-old niece, who described escalating tension in the couple's relationship.