Karen Read’s defense team called a hostile witness to testify on Monday, in the form of a Boston police officer who was assigned to the Canton Police Department on the morning when Karen Read and her two friends found John O’Keefe deceased under a snow pile.

Officer Kelly Dever, who was on duty that morning but had no involvement in the investigation, had previously informed the FBI that she observed two important individuals in the case standing near Read’s SUV in the sallyport at Canton’s police headquarters for an unusually long duration. These individuals were ATF Agent Brian Higgins — who was engaged in a clandestine relationship with Read unbeknownst to O’Keefe — and the then-Canton Police Chief Kenneth Berkowitz.

They would have been placed next to the vehicle before other investigators found fragments that matched Read’s taillight at the crime scene.

Retired Massachusetts Superior Court Judge and Boston College professor Jack Lu described Dever as “a profile in courage” and noted that her appearance in court might indicate a sense of urgency or last-resort tactics by the defense.

“She’s out of central casting, says that she has confirmed her prior memory is factually, irrefutably wrong,” he told Fox News Digital. “If they say she has damaged her future ability to testify that is laughable.”

She’s also facing blowback. Lu pointed to a Facebook group called Free Karen Read with more than 40,000 members, where a user urged others to call the police commissioner’s office if they “believe Kelly Dever should be given the axe.”

Dever could not immediately be reached for comment.

It’s up to the jurors to decide whether she was truthful on the stand or when she first made her statements to the FBI.