SAN FRANCISCO (KRON) – Just hours before tech mogul Bob Lee was 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 Nexstar’s KRON.

Momeni wanted to know if Lee had done anything “inappropriate” with Momeni’s younger sister, the witness said, according to court documents filed by prosecutors.

Lee, 43, was 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.

Momeni was arrested at his home in Emeryville, California. He was charged with murder and booked into a San Francisco jail Thursday.

Prosecutors, seeking to prevent Momeni from being granted bail, filed court documents containing witness statements and allegations of what led to the killing.

On April 3, the documents allege that Lee spent hours hanging out with friends and drinking inside luxury hotels and apartments. At one point during the day, a witness claims to have seen 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.

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 p—-s,” according to court documents.

After Momeni’s alleged 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 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.

Elyassnia lives in San Francisco’s South of Market district with her husband, District Attorney Brooke Jenkins said. Lee went to the residential high-rise she and her husband share 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.

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.

Lee was found and transported to the Zuckerberg San Francisco General Hospital and Trauma Center, where he was pronounced dead.

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.

“We can confirm that Mr. Lee and Mr. Momeni knew each other,” Scott said. “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.”