A witness set to testify in the Karen Read murder trial name-dropped Bruins legend Zdeno Chara while talking about his prior experience in biomechanics, as he helped work on safety advancements to the glass used around NHL games.

Andrew Rentschler, a senior biomechanist and an expert in accident reconstruction, helped the National Hockey League design safer glass between team benches following Chara’s massive hit on Max Pacioretty of the Montreal Canadians in 2011.

Rentschler and his colleague Daniel Wolfe, both PhDs who work for engineering consulting firm ARCCA, sat for a voir dire, or preliminary questioning by attorneys, last Tuesday without jurors present. Judge Beverly Cannone ruled the two may testify for the defense.

“The NHL came to us to see if we could have a redesign of the rink to make it a little safer,” Rentschler said last week. “Now in every arena in the NHL, it is basically a curved piece of springloaded … plexiglass where the players now hit into it, it absorbs the impact, and they glance off of the glass.”

“Somewhat ironically,” he said from Norfolk Superior Court in Dedham, squarely within Greater Boston, “it was Chara hitting Pacioretty into the glass, the Boston-Montreal game, and it caused a cervical fracture and concussion” that led to the project.

Rentschler and Wolfe are expected to testify Monday regarding an independent analysis they performed of the likelihood that Boston Police Officer John O’Keefe’s Jan. 29, 2022, death was caused by a vehicle-pedestrian strike.

Prosecutors say that O’Keefe’s girlfriend of two years, Karen Read, 44, of Mansfield, struck him with her SUV following a drunken argument and left him to die in a snowstorm in front of 34 Fairview. She faces charges including second-degree murder. Defense attorneys counter that outside actors killed O’Keefe and conspired with state and local police to frame Read for his murder.

Her attorneys Alan Jackson and David Yannetti said Friday they estimate they will rest their case Monday, with closing arguments on Tuesday.

Cannone on Thursday said Rentschler’s testimony may be limited because only medical doctors and not biomechanical engineers can testify to the causes of death under Massachusetts law. Rentschler said he is an expert in the movement of the human body.

Chara’s hit on Pacioretty happened with 15.6 seconds left in the second period of the Bruins-Canadians game on March 8, 2011. Pacioretty was chasing down a loose puck along the boards in the neutral zone when Chara rode him into the boards.

It looked like a routinely rugged play until Pacioretty hit his head and neck on the partition between the two benches. He appeared to be out cold when he hit the ice, where he remained face-down for several long and tense minutes.

Tests on Pacioretty for internal bleeding were negative, though he was diagnosed with a severe concussion and fractured fourth cervical vertebrae.

The hit prompted an investigation, but Quebec’s director of criminal prosecutions, months later, closed the case, saying it was unlikely a court would find Chara guilty of a crime.

Wolfe is ARCCA’s director of accident reconstruction and he said that the agency who hired his firm had “open-ended” questions about the likelihood that O’Keefe’s injuries were the result of a vehicle strike.

Prosecutor Adam Lally argued during the voir dire that he had some concerns over one of the four conclusions the pair made in their report. He said the conclusion, which he didn’t describe, was outside the scope of their expertise. Defense attorney Jackson argued otherwise.

Members of the Montreal Canadiens medical staff and players put Max Pacioretty on a stretcher after being body checked by Zdeno Chara of the Boston Bruins during the NHL game at the Bell Centre on March 8, 2011, in Montreal, Quebec, Canada. (Photo by Richard Wolowicz/Getty Images)

Karen Read and attorney David Yannetti during her murder trial on Wednesday (Pool Photo by Greg Derr)

Dr. Andrew Rentschler, of ARCCA, testifies during the murder trial of Karen Read at Norfolk Superior Court on June 18. (Staff Photo By Stuart Cahill/Boston Herald)