Karen Read's SUV reached '74% throttle' moments before John O'Keefe's final movements, crash expert testifies

Karen Read's trial sees crash expert data placing her at the scene of John O’Keefe's death, as prosecution strengthens its case in Massachusetts.

On Tuesday, special prosecutor Hank Brennan called the state’s likely final witness to the stand. Dr. Judson Welcher, an accident reconstructionist and biomechanical engineer with Aperture LLC, testified that the black box data within Read’s vehicle did not register a collision on the morning of O’Keefe’s death, but he insisted the lack of data is expected because the system only registers car-to-car crashes, not pedestrians. Julia Bonavita is a U.S. Writer for Fox News Digital and a Fox Flight Team drone pilot. You can follow her at @juliabonavita13 on all platforms and send story tips to julia.bonavita@fox.com.

"Were you surprised that there was no information about a collision in the [black box]?" Brennan asked.