Karen Read looks toward her defense attorney Robert Alessi, as special prosecutor Hank Brennan questions Ian Whiffin, a digital intelligence expert with Celebrite, about the data on John O'Keefe's iPhone during her murder retrial in Norfolk Superior Court in Dedham, Mass., Monday April 28, 2025. (Pat Greenhouse/The Boston Globe via AP, Pool) AP

Cellebrite expert Ian Whiffin walked jurors through one of the most contentious pieces of evidence in Karen Read’s case Monday.

Karen Read 's second murder trial is now underway. But this trial is not it for Read's legal troubles. Read, 45, is accused of killing her boyfriend, Braintree native and Boston police officer John O'Keefe outside a Canton home in January 2022. Read's first trial in O'Keefe's death ended in a mistrial in July.