Jurors will begin deliberating the fate of Karen Read, a Mansfield woman accused of murdering her boyfriend John O’Keefe outside a Canton home in 2022, today after sitting for testimony over the better part of two months. Both sides will present their final arguments to jurors this morning.

The prosecution

Read, 44, faces charges of second-degree murder, motor vehicle manslaughter and leaving the scene of a collision causing the death of O’Keefe, a 16-year Boston Police officer when he died at age 46 in the early morning hours of Jan. 29, 2022. Her trial began on April 29 and has spanned 30 in-court days at Norfolk Superior Court in Dedham, including 29 days of testimony.

Prosecutors have argued that taillight pieces found at the snowy scene of O’Keefe’s death on the front lawn of 34 Fairview Road in Canton, heavy drinking the evening before, and a demonstrated history of jealousy and unrest in the relationship between Read and O’Keefe points to her guilt. Prosecutor Adam Lally argues the Mansfield financial analyst and Bentley University lecturer purposely struck him with her car as she dropped him off at that house sometime after midnight.

To expand on this theory, prosecutor Adam Lally called on 68 witnesses. The cast included minor figures like people who had just had some drinks with Read and O’Keefe in the hours before his death but weren’t that close, to long-time friends who could opine on any changes to the relationship. There were some witnesses whose role was similarly limited but critical, like two sisters who testified that Read blew up at O’Keefe during a trip to Aruba when she suspected that he made out with another woman.

Then there were the Canton cops and paramedics who testified, variously, that Read either made incriminating statements at the scene of O’Keefe’s death like “I hit him, I hit him, I hit him” or that she simply questioned whether she could have hit him. Then there were the Massachusetts State Police investigators who detailed their case, from locating broken taillight fragments and a drinking glass resembling the one O’Keefe left his last bar with as well as a single shoe and his hat buried in the snow. Forensic scientists testified that a hair below the taillight of Read’s vehicle made a match to O’Keefe to a stupendously high mathematical degree.

The defense

The defense has a significantly different view of the case. During cross-examination of prosecution witnesses, the defense slowly built up the idea of a nefarious plot: that someone or multiple people inside 34 Fairview Road — the home whose yard O’Keefe’s body would be found partially buried in the snow — beat him to death and placed his body there. Read’s role in this plot was simply an easy mark for the murderers and those involved in the conspiracy to place the blame so the real murderers could walk free.

Over the last two days of trial, Friday and Monday, the defense called only six witnesses before resting its case.

On Friday, the three witnesses promoted the conspiracy version of events. A Canton snow plow operator testified that he saw another car outside the home during a critical hour. A doctor testified that wounds to O’Keefe’s right arm looked like dog bites and claw marks — the defense has said the dog of the home, Chloe, could have participated in the fatal attack. And a computer forensics expert said that he believed a key witness made the suspicious search “hos long to die in cold” hours before O’Keefe’s body would be found, pointing toward conspiracy.

On Monday, the defense called three more witnesses they used to poke holes in the prosecution’s theory of events. A forensic pathologist backed up the Friday doctor’s dog-bite theory but also testified that no matter what context or additional evidence is present, a vehicle-pedestrian strike would always result in significant bruising to the victim, which O’Keefe did not display. Two consulting forensic scientists originally employed in the federal probe of the investigation, a detail that jurors do not know about, testified that the science does not back the theory of a vehicle strike whatsover.