Daniel Wolfe, a crash reconstructionist for engineering consulting firm ARCCA, testified in the Karen Read trial. WBZ-TV's Tammy Mutasa reports.

The Karen Read trial on Friday focused on controversial testimony about the alleged collision involving Read's SUV and John O'Keefe.

For the final test, ARCCA used a dummy weighing about 200 pounds. A collision between the dummy and the SUV at that speed completely shattered the rear window, dented the SUV liftgate, and popped out the bumper window, Wolfe said.