SAN FRANCISCO (KRON) -- Jury selection for the Bob Lee murder trial is underway on Wednesday as a jury pool of more than 140 San Francisco residents is whittled down. With opening statements slated to begin in a matter of days, defense attorneys are seeking to ban Lee's ex-wife from attending the trial because she allegedly intimidated witnesses. Nima Momeni, 40, of Emeryville, is charged with first-degree murder. Prosecutors said he stabbed Lee in the chest with a knife under the Bay Bridge around 2:30 a.m. on April 4, 2023. On Monday, Momeni's defense attorneys filed a motion requesting for Judge Alexandra Gordon to forbid Lee's ex-wife from the entire 3-month-long trial. Lee, 43, was a wealthy and successful tech mogul. He founded the company Cash App, worked for Google as a software engineer, and served as an executive for MobileCoin. The divorced father of two spent his last two nights alive attending several parties with friends around San Francisco, according to court documents. Khazar, center, arrives for the arraignment of her brother, Nima Momeni, on May 18, 2023 in San Francisco. (Photo by Justin Sullivan /Getty Images) One witness told police that Momeni was angry about Lee’s "inappropriate" behavior with Momeni’s younger sister, Khazar, at one of the parties. Just after midnight on April 4, Lee showed up at Khazar's luxury apartment at the top of Millennium Tower. Surveillance cameras recorded Lee and Momeni leaving Millennium Tower together shortly before Lee was fatally stabbed. Prosecutors said Momeni and Lee knew each other through Khazar, who also went by the name "Tina." Khazar is married to a San Francisco plastic surgeon and witnesses told police that Khazar was in some sort of a romantic relationship with Lee. According to a motion filed this week by defense attorneys, Lee's ex-wife refers to Khazar as "the whore of high tower." Momeni's attorneys are accusing Krista Lee of slandering witnesses who are expected to testify on the stand, including Khazar. The motion includes a screen shot of text messages that Krista Lee allegedly sent to someone asking for information about Khazar's whereabouts. Police were having a tough time finding Khazar and accessing her Millennium Tower apartment, the text message states. Krista Lee talks to reporters on August 1, 2023 in the San Francisco courthouse. (KRON4 photo / Amy Larson) Attorney Anthony Brass wrote in the motion, "Clearly, Krista Lee feels emboldened by something, acting as an un-deputized agent of the SFPD to surreptitiously contact and slander witnesses, specifically the defendant's immediate family, and use her influence to intimidate witnesses to do her bidding." "The defense believes that Krista Lee has been 'playing detective' on many occasions and has no intention of stopping," Brass wrote. Death of Cash App founder Bob Lee ‘still stings,’ ex-wife says Momeni has pleaded not guilty. If convicted of first-degree murder, he will face a lengthy prison sentence. Khazar wrote a letter to the judge last year defending her brother’s character. "He watches out for me. Nima is one year older than I am. We have been together our entire lives. My brother means the world to me. I don’t believe we could live without each other," she wrote. Nima Momeni walks into the courtroom in San Francisco on May 2, 2023. (Gabrielle Lurie/San Francisco Chronicle via AP, Pool, File) Defense attorneys also accused Krista Lee of tampering with another key trial witness, Jeremy Boivin. Boivin is an alleged drug dealer who hosted one of the parties that Lee and Khazar attended on April 3, 2023. Lee’s autopsy report revealed that he had multiple "party drugs" in his system when he was slain, including cocaine and ketamine. Boivin called a San Francisco Police Department detective last month that he had been talking with Krista Lee and she urged him to talk to police, according to the motion. "For whatever reason, she is being permitted to actively influence others. This further supports the defense's request to exclude Krista Lee from the courtroom during the course of the trial," Brass wrote. The detective recorded a phone conversation with Boivin on Sept. 17, 2024 and asked "How long have you known Bob Lee and his family?" Boivin answered, "I think we met in 2019? We met, like, after a club one night. He came over." Lee and his wife reportedly divorced in 2019 and the tech mogul moved out of their Mill Valley house. Khazar, center, arrives for the arraignment of Nima Momeni, her brother, at the Hall of Justice in San Francisco, Thursday, May 18, 2023. (AP Photo /Godofredo A. Vásquez) Boivin told the detective that, even after the homicide, he still hangs out with Khazar and he recently went to her birthday party. SFPD Detective Brent Dittmer asked Boivin several questions about providing Lee and Khazar with drugs, but the alleged drug dealer refused to answer. "When Bob was not under the influence of drugs, what we he like?" the detective asked. Boivin answered, "He was always in a good mood and trying to help people out." The detective asked if Lee every got into fights or displayed a temper. Boivin answered, "Not even a little bit. Zero ego or temper. He was cool as hell. I'd trust him with anyone, anything in my life. I'd leave my girlfriend with him, I'd leave my cats with him. He's 100 percent a solid dude. He'd take care of whatever you needed. He's a really sweet guy. A soft kind of guy. I've never seen him once talk aggressively to somebody." Homicide victim Bob Lee Boivin said he had never met Khazar until he went with Bob Lee to her house on April 3, 2023. Khazar, Bob Lee, and Boivin spent the entire day together partying, going to the beach, and hanging out at a pool, court documents state. When they ended up in Boivin's apartment in the afternoon, Boivin gave Khazar and her female friend a "date rape drug" known as "GHB," Dittmer previously testified at a preliminary hearing. The friend told police that she passed out, and when she regained consciousnesses, Khazar was wearing only a bikini and crying. Neither woman felt safe at the party and Momeni picked them up to bring his sister home, the friend told police. During the September 17 recorded phone conversation, Boivin told the detective, "I didn't do anything wrong to either of those girls. I was cordial, and trying to be hospitable of course. When they felt ill, I helped them. I called Nima (Momeni). I was talking to Nima on the phone." A motion recently filed in court by defense attorneys states that Bob Lee's ex-wife refers to Khazar as "the whore of high tower." (KRON4 Photo) The alleged drug dealer had never met Momeni before. When Momeni showed up to pick up Khazar, Boivin said he seemed like "a hot-head" and "a bully. He seemed angry for sure." Bob Lee was not slain in ‘honor killing,’ defense says The detective asked, "About what?" Boivin replied, "Her just being out and about. I guess." Boivin said Momeni could have also been angry that Khazar's female friend was at the party because she "had slept with Nima the night before," Boivin said. During jury selection on Wednesday, members of the jury pool were asked about their opinions on illicit recreational drug use and the Bay Area tech industry. One man said he works in tech and is familiar with San Francisco's tech party scene. A prosecutor asked another potential juror if he viewed illicit drug use as a "moral failing" that would impact his judgement of a homicide victim. The man answered, "Depends on what kind of drug was used. Meth would be worse." The prosecutor asked, "Can you be fair if someone was using drugs?" The man replied, "Absolutely." On the first day of jury selection Tuesday, assistant district attorney Omid Talai asked potential jurors if they could be fair and impartial, even without a clear motive behind the killing. Nima Momeni's defense attorneys gather outside the courtroom on Oct. 8, 2024 for the first day of jury selection. (KRON4 Photo) "This is not 'Law and Order,'" Talai said. "Every single question you have may not be answered. The prosecution is not required to give a motive in a murder, for instance. I’m not saying that will, or will not, happen. That could be a question that could go unanswered. Anyone have trouble with that?" Potential jurors under examination indicated they would not have trouble with that. Defense attorney Saam Zangeneh asked potential jurors questions about the right to self defense. Each replied that they thought a person had a right to defend themselves from an attack. Former prosecutor and legal analyst Steven Clark said he expects there to be two competing narratives during trial. "For the prosecution this is pre-meditated murder. For the defense they are saying that Momeni is acting in self-defense and he’s completely innocent," Clark told KRON4. Both the defense and prosecution will work to get their versions of what happened to Bob Lee out in front of jurors early. The case has attracted nationwide attention, and attorneys are attempting to select fair and impartial jurors from the jury pool. Jury selected and scheduled to continue through Thursday. Krista Lee previously told KRON4 that beyond splashy news headlines, her ex-husband should be remembered for who he was -- a loving father and a gentle, respectful person. "Bob was an amazing and sweet man," she said. The trial will last until mid-December, the judge said. Opening statements are set to begin on Monday, October 14.