In the second murder trial of Karen Read, Jennifer McCabe's testimony emerged as crucial, as she provided a firsthand account of the events surrounding the death of Boston police officer John O’Keefe. McCabe was present at pivotal moments, including a gathering at a bar, an after-party at her sister’s home, and the subsequent discovery of O’Keefe’s body. The prosecution views McCabe as a reliable witness, while the defense accuses her of participating in a cover-up to frame Read. During cross-examination, defense attorney Alan Jackson challenged McCabe’s credibility and memory, highlighting her familial ties with law enforcement and questioning inconsistencies in her account. The trial also examined forensic evidence related to Read’s blood alcohol level, which suggested she was significantly over the legal limit at the time of the incident.

Jennifer McCabe, considered a key witness, provided a detailed account over three days of testimony, describing her interactions with O’Keefe and her observations of Read's behavior the night of his death.

Prosecutors relied on McCabe to substantiate their case, as her testimony included corroborated phone records and her presence at critical moments leading to the discovery of O'Keefe's body.

The defense sought to undermine McCabe's credibility, suggesting she was involved in a cover-up and pointing to her communications with law enforcement and family members as potential evidence of collusion.

McCabe's testimony included claims that Read admitted to hitting O’Keefe, which the defense argued was not consistently reported to law enforcement, casting doubt on the reliability of her statements.

Defense attorney Alan Jackson questioned McCabe about her decision-making during the crucial moments when O'Keefe was found, particularly why she did not seek immediate assistance from trained law enforcement present at the scene.

Forensic analysis presented in court aimed to establish Read's blood alcohol content at the time of the incident, indicating a level much higher than the legal limit, a point contested by Read who criticized the assumptions used in the analysis.

The trial continues to balance the prosecution's portrayal of McCabe as a credible eyewitness against the defense's narrative of a conspiracy to frame Karen Read for O’Keefe’s death.