The alleged Karen Read-John O'Keefe crash, reconstructed in court

It was a key day in the Karen Read murder trial as biomedical engineer Judson Welcher, a prosecution crash reconstruction expert, showed highly detailed video that illustrated what he said the data shows about Read's SUV and John O'Keefe's death — but his testimony ended with a dramatic objection over his conclusion on what happened. We break down what the jury saw — and what they missed while out of the courtroom — as well as what the defense's addition of four new witnesses may suggest about their strategy, which will reveal itself when they soon present their case in chief.