Boston Police Officer John O'Keefe's niece told jurors that his relationship with his suspected killer began to deteriorate in the weeks before his death.O'Keefe, 46, was found dead on Jan. 29, 2022. His then-girlfriend, 45-year-old Karen Read, is currently on trial in connection with his murder.The niece, whose name is not being disclosed because she is a juvenile, testified Wednesday morning after the prior day's testimony was canceled abruptly minutes before it had been scheduled to start.MEDICAL EXAMINER DETAILS SKULL FRACTURES IN KAREN READ MURDER TRIAL TESTIMONYWATCH KAREN READ TRIAL LIVE ON FOX NATION, HOSTED BY PAUL MAUROTo protect the juvenile's privacy, the judge also ordered news cameras not to record her testimony, but the court reserved space for 10 reporters inside the courtroom."This was someone who, to me, could not hide her animosity toward Karen," said John DePetro, a New England radio host who was in court for the proceedings. "The things she said were significant there was a lot of fighting in December and January, and the fighting seemed to increase."KAREN READ TRIAL: CRIME LAB EXPERT TESTIFIES BLOOD EVIDENCE WAS NEVER TESTEDThat aligns with the timing of an argument Read allegedly picked with O'Keefe after a New Year's trip to Aruba, where she accused him of cheating on her with a friend's sister something that O'Keefe denied, according to his niece."On more than one occasion after they had fought, the niece said John had said to [Read], Why dont you just go home?'" he told Fox News Digital. "And she wouldn't leave the house."KAREN READ'S DEFENSE OPENS DOOR FOR SPECIAL PROSECUTOR TO BRING IN NEW EVIDENCE: COURT DOCSAnother key part of the niece's testimony is from the morning Read and two other women found O'Keefe dead outside 34 Fairview Road in Canton, a suburb about 20 miles south of Boston.She testified that a "frantic" Read woke her up between 4:30 and 5 a.m. on Jan. 29, 2022, according to Ted Daniel of WFXT-TV, who was also in the courtroom. Read wanted phone numbers for O'Keefe's friends, Kerry Roberts and Jennifer McCabe, who were with Read at roughly 6 a.m. when they discovered O'Keefe unresponsive under a dusting of snow.GET REAL-TIME UPDATES DIRECTLY ON THE TRUE CRIME HUBThe niece allegedly overheard her asking whether she could have "done something" or if O'Keefe may have been "hit by a plow."FOLLOW THE FOX TRUE CRIME TEAM ON X"I dont think it damaged the defense case, and I think some people were expecting she would be very harsh about Karen Read," said Grace Edwards, a Massachusetts defense attorney who has been following the case."But it appears she told it like it was and was not biased against her. She testified to things already in the record with respect to their relationship we already saw the text messages between them and there was no evidence of any physical violence."SIGN UP TO GET TRUE CRIME NEWSLETTERRead could face up to life in prison if convicted of the top charge, second-degree murder.She has pleaded not guilty, and her defense denies her vehicle collided with O'Keefe at all.Fox News' Julia Bonavita contributed to this report.