The defense in the retrial of Karen Read, accused of killing her boyfriend John O’Keefe, called its first witness Friday.

As CrimeOnline previously reported, O’Keefe, an off-duty Boston police officer, was found dead in the snow outside a friend’s Canton home. Read, 45, a former adjunct professor at Bentley University, has pleaded not guilty to second-degree murder and other charges.

Her first trial ended in a mistrial.

Prosecutors alleged that Read reversed her Lexus SUV and struck O’Keefe shortly after midnight on January 29, 2022, after the couple attended a gathering with friends.

Read’s defense team called Matthew DiSogra, an engineer from the motor vehicle accident reconstruction firm DeltaV, to the stand Friday morning.

According to USA Today, DiSogra reviewed the work of prosecution witness Shanon Burgess, a digital forensics expert who tried to resolve differences between data from Read’s SUV and O’Keefe’s iPhone.

Using clock data from both the phone and vehicle, Burgess built a timeline for the night O’Keefe died that could link Read to the crime. He said O’Keefe’s phone last locked during the brief moment Read’s car recorded a backup maneuver.

DiSogra told jurors that phone and car clocks typically don’t match exactly. He said his own analysis showed the phone’s last lock happened after the car backed up.

Defense attorney Alan Jackson asked the judge to dismiss the charges against Read, arguing the prosecution failed to prove a collision happened on January 29, 2022, or that Read intended to kill O’Keefe. He called the case a “vindictive prosecution.”

Prosecutors argued that they presented evidence showing Read was over the legal alcohol limit and that a collision occurred at 34 Fairview Road, where O’Keefe’s body was found. They also cited numerous voicemails Read left O’Keefe and her own statements to police, suggesting she may have hit him.

Read claimed she never hit O’Keefe with her vehicle, with reported claims that he he was beaten up inside the residence and then attacked by a dog.

The trial continues. Check back for updates.