The letter, addressed to Boston Police Commissioner Michael Cox and obtained exclusively by 25 Investigates, alleges Officer Kelly Dever’s credibility is “irreparably compromised”.

Boston Police officer Kelly Dever, formerly with Canton Police, testifies during the murder retrial of Karen Read in Norfolk Superior Court, in Dedham, Mass., Monday June 2, 2025.

Boston Police Officer Kelly Dever, formerly with Canton police, testifies. Pat Greenhouse / The Boston Globe. By Abby Patkin. updated on June 2, 2025 5 minutes to read.

Boston Police officer Kelly Dever, formerly with Canton Police, testifies during the murder retrial of Karen Read in Norfolk Superior Court, in Dedham on Monday.

Boston Police Officer Kelly Dever worked at the Canton Police Department the morning Karen Read and two other women found John O'Keefe dead in the Beantown suburb -- but she did not investigate ...

Boston Police Commissioner Michael Cox was asked Thursday for the first time about references to him and his department during testimony in the Karen Read trial.