As Karen Read’s second murder trial enters its sixth week, an accident reconstruction specialist has taken the stand at Norfolk Superior Court in Massachusetts.

The Boston Globe reported that Judge Beverly Cannone informed the jury last week that the trial is currently ahead of schedule, with an expected completion time of six to eight weeks.

As noted by CrimeOnline, prosecutors allege that on January 29, 2022, Read, 45, accidentally ran over her boyfriend, Boston police officer John O’Keefe, after a night out bar-hopping. The incident occurred when she allegedly backed her SUV into him outside a Canton residence.

Her defense lawyers claimed she had been framed and that O’Keefe entered the house, owned at the time by a fellow Boston officer, where he was fatally beaten and possibly attacked by a German Shepherd before his body was planted on the lawn.

On Tuesday, accident reconstructionist Dr. Judson Welcher answered questions during a brief “voir dire” while the jury remained outside the courtroom, according to NBC 10. 

After the jury entered the courtroom, Welcher began his testimony. 

He compared the clock in Karen Read’s SUV to the time on O’Keefe’s phone and walked the jury through a simulation showing a three-point turn used to sync the clocks.

Welcher then identified a second “trigger” in the SUV’s data, which he said marked the alleged collision. He said the vehicle reversed 53 feet at 74% throttle.

Investigators said they found a broken glass, a black straw, and O’Keefe’s missing shoe away from the scene—evidence State Police Sgt. Yuri Bukhenik said during testimony earlier this month supported the theory that a vehicle struck O’Keefe.

Bukhenik previously testified that when he saw O’Keefe at Good Samaritan Hospital, he had severe injuries to his face and head and cuts on his right arm.

CBS News reports that the defense emphasized that Bukhenik didn’t go into 34 Fairview Road in Canton, where the gathering took place, and did not request a search of the home. He also highlighted that Bukhenik interviewed people who were at the residence that night, and argued that each had potential motives to lie if they played a role in O’Keefe’s death.

Prosecutors could reportedly finish presenting their case this week. Check back for updates.