San Francisco prosecutors have released surveillance images that they say show Cash App founder Bob Lee and his suspected killer on the night of his death in early April.
Nima Momeni, the 38-year-old suspect, allegedly took issue with Lee’s interactions with his married sister hours before the deadly stabbing.
One image, taken in an elevator on Khazar Momeni’s luxury Mission Street apartment building, appears to show Lee gesturing at her brother to look him in the eyes as they speak.
According to prosecutors, the two had a rocky night before Momeni allegedly stabbed Lee with his sister's kitchen knife in a parking lot nearby.
This surveillance image shows Bob Lee and Nima Momeni in an elevator, according to San Francisco prosecutors. (KTVU)
On Tuesday, Momeni's defense attorney, Paula Canny, filed a motion with the court for permission to withdraw from the case due to an unspecified conflict of interest.
"It’s both with great disappointment and relief that I’m here," she told reporters outside the courtroom. "It’s just a super messed-up situation. S--- happens in representing people."
At a prior hearing, she told reporters that Lee's death had been an accident and self-defense.
The sister of Bob Lee murder suspect Nima Momeni, Khazar Momeni, right, and her husband, Dr. Dino Elyassnia, own a condo in the luxury San Francisco building where local reports say police served a search warrant in connection with the murder investigation. (Bob Lee/Instagram | Dr. Dino Elyassnia/Instagram)
Momeni, a Silicon Valley outsourcer, pleaded not guilty this month ahead of his arraignment on murder charges in Lee's death.
Police arrested the Iranian national on April 13, nine days after allegedly stabbing the 43-year-old tech titan in a dispute over his sister, Khazar, the wife of a prominent San Francisco plastic surgeon.
This surveillance image shows Bob Lee and Nima Momeni in an elevator, according to San Francisco prosecutors. (KTVU)
CASH APP FOUNDER BOB LEE'S SAN FRANCISCO STABBING LINKED TO ‘SEX AND DRUGS’ PARTY LIFESTYLE: REPORT
A witness told police that the suspected killer had confronted Lee earlier in the evening for allegedly using drugs with his sister, according to court documents.
Later that evening, the two were seen on surveillance video leaving an apartment building together and getting into Momeni's car.
This surveillance image shows Bob Lee and Nima Momeni before Lee's fatal stabbing, according to San Francisco prosecutors. (KTVU)
They drove to a parking lot, where court documents say Lee was stabbed through the heart with a kitchen knife and was seen stumbling down Main Street in San Francisco's Rincon Hill neighborhood, begging passersby for help and then calling 911 himself.
This surveillance image shows Bob Lee and Nima Momeni getting into Momeni's car, according to San Francisco prosecutors. (KTVU)
In court on May 18, lawyers revealed the knife had come from Khazar Momeni's kitchen and allegedly had her brother's DNA and Lee's blood on it.
Lee died in the hospital where doctors performed an emergency thoracotomy, a cut through the rib cage, in an attempt to treat his wounds, according to the autopsy report.
Nima Momeni is shown in a San Francisco courtroom on May 30. He is charged with fatally stabbing Cash App founder Bob Lee. (KTVU)
Court documents obtained by Fox News revealed that investigators helped piece together the crime by reviewing text messages exchanged between Lee and his suspected killer's sister.
In one conversation, she reportedly told Lee that he "handled himself with class" after her brother allegedly "came wayyyyyy down hard" on him.
Nima Momeni carries files in a San Francisco courtroom on May 30. (KTVU)
The texts were revealed as part of District Attorney Brooke Jenkins' motion to ask the court to keep Momeni behind bars until his next hearing.
"[Momeni] drove [Lee] to a dark and secluded area the opposite direction of his hotel," the filing states. "We know through a text message from Defendant's sister to Victim, Defendant was previously upset with Victim and ‘came down hard on’ him."
Khazar Momeni, the sister of stabbing suspect Nima Momeni, reportedly exchanged text messages with victim Bob Lee, according to court documents. (Vincent Gotti Photography)
According to the documents, an unnamed witness told police that Lee was drinking with his suspected killer's sister the afternoon before his murder.
Bob Lee and his family are shown in an undated Facebook photo. The tech innovator recently described his new home in Miami as feeling like "Silicon Valley in the early 2000s." He returned to San Francisco to visit and was fatally stabbed. (Bob Lee/Facebook )
"Witness 1 was unsure if Victim and Female had an intimate relationship," the filing states, but it also notes, "Female was married, but the relationship had possibly been in jeopardy."
That evening, the witness told police Momeni was grilling Lee in his hotel room about "whether his sister was doing drugs or anything inappropriate."
Lee tried to assuage Momeni's concerns, the witness said, and left his hotel room after midnight.
Cash App founder Bob Lee is shown in an undated photo. (Bob Lee/Facebook)
Police obtained surveillance video from the residential building that showed Lee and Nima Momeni getting into an elevator just after 2 a.m., according to Jenkins' office. They got into Momeni's white BMW and drove around the corner.
By 2:30 a.m., Lee appeared on surveillance video nearby, stumbling with stab wounds to his torso. The autopsy found he'd been stabbed three times, once in the hip and twice in the chest, including a wound that pierced his heart.
Fox News' Michael Lundin contributed to this report.