SAN FRANCISCO (KRON) — Just hours before tech mogul Bob Lee was brutally stabbed to death in San Francisco, a witness overheard a conversation between the Cash App founder and his accused killer, Nima Momeni, according to court documents obtained Friday by KRON4.

Momeni wanted to know if Lee had done anything “inappropriate” with Momeni’s younger sister, according to the witness. A possible motive behind Lee’s shocking homicide was revealed in court documents filed by prosecutors.

Lee, 43, is a divorced father of two who made millions working in the San Francisco Bay Area tech industry. Momeni, 38, is a Bay Area tech entrepreneur. Prosecutors believe Momeni stabbed Lee in the chest twice –including once in the heart — around 2:30 a.m. on April 4, and left him in the street to die.

Khazar Elyassnia, left, stands in the Hall of Justice in San Francisco on Friday, April 14, 2023, ahead of an appearance by her brother, Nima Momeni, who has been charged with murder in the death of tech entrepreneur Bob Lee. Elyassnia’s husband, Dino Elyssania, is to her right. (AP Photo/Olga Rodriguez)

Momeni was arrested at his Emeryville home, charged with murder, and booked into a San Francisco jail Thursday. To make sure Momeni remains behind bars without bail, prosecutors filed court documents containing grisly details about what led up to the killing.

On April 3, Lee spent hours hanging out with friends and drinking inside luxury hotels and apartments. At one point during the day, a witness saw Momeni confront Lee about Lee’s relationship with Momeni’s younger sister, Khazar Elyassnia.

The witness was unsure if Lee and Elyassnia had engaged in an “intimate relationship,” court documents state. Elyassnia is married, “but the relationship had possibly been in jeopardy,” prosecutors wrote.

Bob Lee
Bob Lee

The tense verbal confrontation happened inside Lee’s hotel room at 1 Hotel San Francisco, the witness said. Momeni “was questioning (Lee) regarding whether his sister was doing drugs or anything inappropriate. (Lee) had to reassure (Momeni) nothing inappropriate happened,” prosecutors wrote.

Elyassnia later sent Lee a text message praising him for being “classy” about how he handled her brother’s suspicions, court documents state.

Investigators found a text message from Elyassnia that she sent to Lee after they had hung out on April 3. She wrote, “Just wanted to make sure your doing ok. Cause I know my nima came down wayyyyyyy hard on you. And thank you for being such a classy man handling it with class. Love you Selfish pricks,” according to court documents.

Khazar Elyassnia was surrounded by media cameras in the hallway of the San Francisco courthouse before she entered a courtroom. (Photo by Dan Kerman / KRON4)

After Momeni’s tense conversation with Lee, the witness went with Lee to his apartment to “hang out.” Lee left the apartment at 12:30 a.m. on April 4, and the “witness never saw victim again,” prosecutors wrote.

Momeni is currently in jail with no bail. He made his first court appearance on Friday and did not enter a plea. Elyassnia and her husband sat in the courtroom gallery. Momeni formed his hands into the shape of a heart in the courtroom, and his family did the same. The judge barred media cameras, but a courtroom sketch artist sketched the moment.

The judge ordered artist Vicki Behringer to only sketch Momeni’s silhouette. Behringer was allowed to sketch his family members in the gallery. (Sketch by Vicki Behringer)

Elyassnia lives at Millennium Tower in SoMa with her husband, District Attorney Brooke Jenkins said. Lee went to the tower on the morning he was slain, Jenkins said.

While speaking to reporters Friday afternoon, Jenkins declined to say if Lee, Elyassnia, and Elyassnia’s husband were tangled in a “love triangle.”

Surveillance cameras recorded Lee entering Millennium Tower at 12:39 a.m. on April 4, court documents revealed. At 2:03 a.m., cameras show Lee and Momeni riding an elevator down to the tower’s lobby. “The two gentlemen in the early morning hours leave the Millennium Tower together,” Jenkins said.

Cameras recorded the two men getting into Momeni’s white BMW. Momeni can be seen in the driver’s seat and Lee in the front passenger seat as the BMW drives down the 400 block of Main Street, documents state.

Momeni “drove victim to a dark and secluded area the opposite direction of his hotel,” prosecutors wrote.

Police found an additional camera that shows the BMW stopping and two men stepping out of the car. The camera is too far away to distinguish the men’s faces, prosecutors said. The men talk for about five minutes before one makes a sudden movement toward the other. The men separate, and moments later, another camera recorded Lee when he is injured and walking on Main Street.

Detectives later found a kitchen knife near the homicide scene, Jenkins said.

Lee’s final moments were recorded by surveillance cameras at Portside apartments in the upscale Rincon Hill neighborhood at 2:35 a.m.. The video shows Lee bleeding and stumbling while trying to find help. Lee approached a car and appears to be begging for help, but the car drove off.

Surveillance cameras at this Portside apartment building recorded the final tragic moments of Bob Lee’s life. (AP Photo / Jeff Chiu)

By the time police officers found him on the 300 block of Main Street, it was too late. He was pronounced dead at Zuckerberg San Francisco General Hospital and Trauma Center.

Lee was the chief product officer of MobileCoin and creator of Cash App. Momeni is an entrepreneur and the owner of Expand IT, a technology and security company, according to his LinkedIn profile.

Police Chief Bill Scott previously told reporters that he would not discuss a motive in the case. Scott said, “We can confirm that Mr. Lee and Mr. Momeni knew each other. Most people who commit homicides know the people who they kill. This has to do with human nature. Right now, Mr. Momeni is our focus as the single suspect of this case.”

Prosecutors said the knife wounds suffered by Lee showed Momeni had a “direct and clear intent to kill.”