SALEM – A Superior Court judge issued an arrest warrant for suspended Peabody police officer George Sideris, who failed to appear in court on Thursday.Judge David A. Lowy issued the warrant after Sideris, 36, did not appear for a hearing. The judge had given Sideris another day after he did not appear on Wednesday, assuming that Sideris just got his next court date mixed up.Assistant District Attorney Karen H. Hopwood insisted that a warrant be issued on Wednesday, but Lowy declined.”I’ve observed him (Sideris) over the last few hearings and I’m very surprised if he is not here, he is less likely to default,” Lowy said.He explained to defense lawyer Steven J. Rappaport that he would issue a warrant on Thursday if Sideris did not appear, and he did.Rappaport told Lowy Wednesday that he had called Sideris on his cell phone, but his voicemail came on and he left a message, as Rappaport emphasized that Sideris “must have gotten the date wrong.”Sideris, who has been living in an apartment on Walnut Street in Peabody, is charged with beating his then 73-year-old elderly mother, Melpomeni Sideris, into a coma on Thanksgiving Day in 2004 at their Ellsworth Road home in Peabody they shared.Mrs. Sideris, 76, was in a coma for several weeks following the incident and eventually emerged, but never returned home. She currently is living in a Lynn nursing home and Sideris is allowed supervised visits with his mother.Issues concerning Sideris’ mental stability have been in question and delaying a trial, which Sideris insists he wants.Bridgewater State Hospital psychologist Dr. Katherine Herzog says he is not competent to stand trial, but is not a danger to himself or anyone else and does not need to be confined to a mental institution.But the state questioned her report and had their own medical expert, Dr. Malcolm Rogers, examine him and that report, which is not public, has been turned over to the court and attorneys.A competency hearing had been scheduled in June, but since Sideris is now in default, the case has no new court date scheduled.