A biomechanist is expected to return to the stand in the Karen Read retrial today, the 31st day, with testimony to help the defense’s case. Watch the court proceedings live in the player below.

“When you look at the position and configuration … it really wasn’t possible to get a skull fracture by hitting the taillight and not sustain any other significant fractures,” Andrew Rentschler testified Tuesday, the 30th day of Read’s second murder trial.

Judge Beverly J. Cannone said that today is expected to be a full day of testimony. Attorneys predict the jury should get the case by Friday or Monday.

Rentschler, a PhD senior biomechanist with the engineering consultancy ARCCA, was the third defense expert in a row to testify that in his analysis the science doesn’t point to a vehicle strike. He follows Dr. Elizabeth Laposata, a former Rhode Island chief medical examiner, and ARCCA colleague Daniel Wolfe, a PhD who runs the company’s crash reconstruction division.

Read, 45, of Mansfield, faces charges including second-degree murder in the death of her boyfriend John O’Keefe the morning of Jan. 29, 2022.

Prosecutors say she struck O’Keefe with the tail end of her Lexus LX570 SUV at around 12:32 a.m., just as a major snowstorm was picking up, and left him to freeze and die on the front lawn of 34 Fairview Road in Canton.

The defense counters that “there was no collision” and that people inside that address beat O’Keefe to death — with the help of a dog named Chloe — and dragged him to the lawn to suggest a vehicle strike and frame Read.

This is a developing story.