The key witness for the prosecution is likely going to be a reluctant one, as Khazar Momeni made her first appearance on the witness stand Thursday and appeared to want to defend her brother, who stands accused of first-degree murder.Khazar Momeni, whose married name is Elyassnia, was originally scheduled to take the witness stand on Tuesday, but prosecutors first called a series of SFPD officers and a crime scene detective, and on Wednesday called victim Bob Lee's close friend, Borzoyeh "Bo" Mohazzabi, who was with him on the day before he died.On Wednesday, Mohazzabi testified about the phone call he overheard on the afternoon of April 3, in which the accused, Nima Momeni, called Lee on his cellphone to interrogate him about what had gone on with Khazar earlier in the day. The story now emerges that while Mohazzabi and Lee were gathered at the apartment of Jeremy Boivin at 1550 Mission Street that afternoon — a gathering that Mohazzabi described as "pretty chill," per Mission Local — along with Khazar Momeni, the two men left, and were not there when whatever Nima Momeni was upset about occurred. The group was reportedly doing whip-its — or nitrous oxide, something that we later learned, via a DUI arrest, that Khazar Momeni is fond of — and Mohazzabi said there was a "bowl of white powder" on the coffee table, but he did not recall if anyone consumed any of it. He and Lee later went to a couple of bars, he said, and it was after they left, apparently, that a female friend of Khazar's arrived, and the two women took GHB and had some sort of bad reaction to it.Under cross-examination Thursday, per KTVU, Mohazzabi admitted the powder was likely cocaine — he previously said he only did "one whip-it" before leaving — and he said that this was the first he was hearing about Khezar possibly being "drugged."Momeni's defense attorney Saam Zangeneh has presented his theory of the case, which is that Lee was the one with the knife, that he acted out of a drug-fueled "flash of aggression," and that Momeni turned the knife back on him in self-defense. And repeated references to Lee's drug use are meant to support this. Khazar Momeni took the stand Thursday afternoon, and as KTVU reports she admitted to prosecutors that she was using both cocaine and nitrous oxide on that Monday in question. The first question out of the gate as the NY Post reports — because, yes, the Post is covering this trial — was "When was it that you learned your brother had killed Bob Lee?" And they've already kind of caught her in a lie, because she said, "My brother was not the one that killed Bob." The defense actually hasn't taken that position — they just say that Nima Momeni killed Lee in self-defense.Prosecutors moved quickly to asking her about the text she sent to Momeni which she said "you scare me" and "you're fucking psychotic sometimes." She responded, per KTVU, "We're brother and sister... We're bickering when we talk, and then we make up."Day 4 of the Bob Lee murder trial. Nima Momeni’s sister, Khazar, arrives at SF Hall of Justice to testify. pic.twitter.com/tYPG6sKXAr— Chris Young (@cyoungnews) October 17, 2024 Khazar Momeni also tried to side-step questions about the texts she sent to her brother after the media began reporting on Lee's death. She claims not to recall writing, "I’m gonno [sic] get to the bottom of this and find out what happened to Bob," and "I’ll ask or the cops will." Per the Post, she told prosecutors she was under the influence of multiple substances when she sent these texts. Nima Momeni then responded, "I talked to the attorney today about your overdose and attempted rape case," to which Khazar responded, "Lol, you dumb fuck, Bob never touched me. No one did."One detail that has come out in this testimony, which was mentioned also in opening statements, is that Khazar Momeni actually invited Boivin, the man who purportedly assaulted her earlier in the day, over to her apartment to bring her drugs after Lee and her brother left around 2 am on April 4. She admitted that Boivin brought her "a tank" of whip-its, but she denies that she had sexual contact with him."Why did you invite Mr. Boivin to your apartment 10 hours after saying you were sexually assaulted?” the prosecutor asked, per the Post. Explaining that Boivin had abused her in some way in the past, and that she was influenced by experiences in her childhood, Khazar Momeni responded, "I sometimes go back to my abuser."Khazar Momeni is expected to continue testifying on Monday.Previously: Prosecutors Share Texts Between Momeni Siblings In Opening Statement; Defense Blames 'Long-Term Cocaine Bender' For Lee's 'Aggression'Top image: Khazar Elyassnia arrives for the arraignment of her brother Nima Momeni on May 18, 2023 in San Francisco, California. 38 year-old tech entrepreneur Nima Momeni was arraigned today in a San Francisco courtroom in connection with the stabbing murder of Cash App founder Bob Lee. Momeni pleaded not guilty to a murder charge. (Photo by Justin Sullivan/Getty Images)