👋 Welcome Back, Case Crackers!

Every week, we dig into investigations where ordinary lives fracture in sudden, shocking ways. This week’s case takes us to the heart of San Francisco’s tech elite, a world of late-night parties, drugs, and wealth that ended in blood on a dark street under the Bay Bridge.

On April 4, 2023, Cash App founder Bob Lee staggered down Main Street in the Rincon Hill neighborhood, clutching his side, leaving a trail of blood, and screaming into his phone: “Help! Someone stabbed me.” He would be dead within the hour. What followed was an 18-month investigation and a dramatic trial that exposed a world of casual drug use, sexual assault allegations, and a “protective brother” whose rage led to three fatal stab wounds.

On December 17, 2024, a jury found Nima Momeni guilty of second-degree murder. We’ll walk you through the evidence, the DNA that sealed his fate, and the self-defense claim that crumbled under cross-examination. Pay close attention: this is the story of how a “bad joke” became a murder weapon, and how a killer’s calm demeanor couldn’t hide the blood on his hands.

🔍 Full Case Story — The Kitchen Knife, The DNA, & “He Just Went From Zero to 100”

In the early morning hours of April 4, 2023, Tech executive Bob Lee walked up an empty San Francisco street in the early hours of Tuesday gripping his side with one hand and his cellphone in the other, leaving a trail of blood behind him .

According to the San Francisco Standard, Lee can be heard screaming “Help! Someone stabbed me!” in the audio of the 911 call he made with his cell phone prior to officers arriving .

The security camera video showed him walking toward the Portside condo complex and collapsing less than 20 feet from the front door . Police found the father of two bleeding on Main Street at 2:35 a.m., but it was too late .

Bob Lee, 43, the chief product officer of MobileCoin cryptocurrency company and creator of Cash App, had traveled to San Francisco from Miami for a business trip. The toxicology report shows Lee, 43, had cocaine, ketamine and alcohol in his system at the time of the stabbing , though these substances were not indicated as a factor in his death.

Lee had been stabbed three times — in the hip, chest, and heart. The autopsy would later reveal that Lee was stabbed in the chest and hip , with one wound penetrating his heart. He died at San Francisco General Hospital.

For nine days, the case remained unsolved. Early speculation suggested Lee had been the victim of a random street crime in a city struggling with public safety concerns. But that narrative collapsed when police made an arrest that shocked the tech community.

On April 13, 2023, Police arrested Nima Momeni at his home in Emeryville on the morning of April 13. He was booked into a San Francisco jail on one count of murder .

Momeni, 38, was the owner of Expand IT, a Bay Area technology and security company. More importantly, he was the brother of Khazar Elyassnia (née Momeni), a woman who had a “casual sexual relationship” with Lee despite her being married to a prominent San Francisco plastic surgeon.

Chief Scott told reporters on Thursday, “We can confirm that Mr. Lee and Mr. Momeni knew each other. Mr. Momeni is our focus as the single suspect of this case.”

The Hours Before the Murder

The events leading up to Lee’s death began not on April 4, but the day before, April 3, 2023.

At a late-night/early-morning gathering at Khazar’s apartment two days before Lee’s murder, Khazar Momeni testified Lee arrived with Jeremy Boivin, who she alleged in her testimony was a drug dealer . She testified that after everyone left the gathering in which people were consuming cocaine and nitrous oxide “whip-its,” she and Boivin went out together and eventually ended up at his apartment along with a girlfriend she called to accompany them .

What happened next would become the prosecution’s theory of motive.

Khazar said she was on drugs, and only had a hazy memory , but she testified that she and a friend took GHB shots at Boivin’s apartment. She said she later passed out unconscious and woke up twice from a blackout, face down, with her pants down as Boivin grabbed her inappropriately .

Khazar then said she called Nima Momeni, drugged out and crying, telling him she “didn’t even know what country [she] was in.”

After Momeni picked up Khazar, prosecutors said Momeni called Lee in an “angry interrogation,” asking him if Khazar was doing drugs or “anything inappropriate.” However, testimony about this phone call was contradictory. Mohazzabi, the only person to witness the phone call on Lee’s end, said Momeni asked about “the girls getting naked” and sounded “crazy” while Khazar testified that her brother was “very calm and collected.”

The prosecution’s theory was clear: prosecutors said Momeni killed Lee after learning that Jeremy Boivin, who is accused of selling drugs to Lee, allegedly raped Momeni’s sister, Khazar Momeni, earlier that day . Momeni blamed Lee for introducing his sister to Boivin and leaving her with a drug dealer.

But Momeni’s own testimony at trial would undermine this narrative.

The Night of the Murder

Surveillance footage shows Momeni arriving at his sister’s apartment building in a white BMW around 8:30 p.m. on April 3, and later shows Lee entering the building around 12:39 a.m. on April 4 .

A little after 2 a.m., security footage shows Lee and Momeni entering an elevator together and getting into Momeni’s BMW . Additional footage from the area shows the two driving in the car together .

According to Momeni’s testimony at trial, the two men were friendly that night. Defense attorneys showed the jury text messages exchanged April 3, after Momeni called Lee to learn more about Boivin. “Thank u again for talking to me, good timing,” Momeni texted. That message was liked by Lee .

Momeni testified in San Francisco Superior Court about a series of phone calls and text messages the day before the stabbing, in which he tried to piece together whether an outlandish story his sister Khazar Momeni told him was true: that she was sexually assaulted . But Momeni also said that he knew his sister had not been sexually assaulted in the hours before Lee’s killing.

This admission was devastating to the prosecution’s motive theory, but it didn’t help Momeni’s defense.

Momeni said he drove around as they tried to figure out their next step, but when Lee spilled a drink, they pulled over under the bridge. Momeni looked for something to clean up the mess and found a cloth, as well as nitrous oxide his sister had left in the car.

“He took a bunch of the whip-it stuff,” Momeni testified. “He was being silly, chatting, made a bunch of weird noises. I thought he was gonna puke or something, so I followed him out.”

Then, according to Momeni, everything changed over a joke.

“To get out of it, I said what you could call a bad joke,” Momeni said on the stand. “I’d rather go hang out with my family rather than strip clubs,” he said he told Lee.

Nima testified he said to Bob that if it were his last night in town, he’d be hanging out with his family not f***ing around in strip clubs. He says Bob Lee went from 0 to 100 after hearing that, pulled a knife from his pocket and attacked him .

On the stand Momeni described and demonstrated redirecting the knife back at Lee. He testified at some point Lee just walked away, unresponsive to Momeni asking what had just happened. He said he had no idea Lee was fatally injured.

Momeni said he picked up the knife and threw it over the Caltrans fence, but couldn’t explain why in his testimony .

But the physical evidence told a very different story.

The Evidence That Convicted Him

Video then shows the BMW drive to a “dark and secluded area” on Main Street, just out of view for the video to see the interaction between the two men . Eventually, the two subjects, who are unidentifiable by their faces but seem to be wearing the same clothing, appear back in frame. After about five minutes, the subject wearing a white-colored top, consistent with what Momeni appeared to be wearing, “suddenly move(s) toward the other subject,” the document says.

The panel of 12 jurors and five alternates examined the evidence presented by the prosecution, including the seven-inch Joseph Joseph paring knife that was used to stab Lee, red blood splatter clearly visible on the blade. Prosecutors say that knife came from Momeni’s sister’s kitchen in her Millenium Tower apartment.

The DNA evidence was overwhelming.

Oyafuso explained that 98% of the DNA on the blade of the murder weapon belonged to Lee, while 99% of the DNA on the handle of the weapon was Momeni’s.

According to Oyafuso’s testimony, the DNA swab from the knife handle has the possibility of two contributors. Compared to Momeni’s DNA sample, the 99% sample matched by a factor of 1.66 septillions. Lee’s DNA matched the blade by a factor of 2.89 octillion .

The numbers were staggering. The likelihood of the DNA on the knife handle belonging to anyone other than Momeni was astronomically small.

DNA evidence on the knife’s handle linked Momeni to the murder weapon; he testified that he touched it only to toss it over a fence .

But prosecutors weren’t done.

The physical evidence was paired with testimony that called Momeni a “psycho” who put fear into his sister, who at one point threatened to call police if he didn’t explain what had happened to Lee.

In court, Reinstedt showed dozens of text messages sent that night and the next day as evidence of Momeni’s motive for the killing. One text message revealed that Momeni believed someone had raped Khazar. “I talked to the attorney today about your overdose and attempted rape case,” Nima Momeni said in a message to Khazar sent after Lee’s death. She replied saying, “Lol, you dumb f—k, Bob never touched me, No one did.”

The Trial and Cross-Examination

Nima Momeni spent his second day testifying during his own murder trial Thursday sparring with the main San Francisco assistant district attorney prosecuting the case, interrupting him repeatedly and accusing him of trying to jostle the defendant toward saying he purposely stabbed tech mogul Bob Lee to death in 2023.

Prosecutor Omid Talai set the combative tone from the start, telling Momeni several times to stop interrupting, refusing his requests to display evidence on a courtroom screen and trying to catch him in contradictions of his self-defense story.

On cross examination, prosecutor Omid Talai hammered Nima Momeni about the idea that Bob Lee, a beloved man in the tech world, wanted to kill him over a bad joke.

Video evidence shown to the jury showed Lee walk for about a block after he was stabbed before collapsing on the street. On Thursday afternoon, Momeni seemed to suggest Lee could have been killed by another person altogether.

Prosecutors called several witnesses who testified that even under the influence of drugs and alcohol, Lee was never aggressive and was a friendly person. One witness, a former Google co-worker who partied with Lee, even called him a “teddy bear.”

The Verdict

On December 17, 2024, after seven days of deliberation, A San Francisco jury has found tech consultant Nima Momeni guilty of second degree murder in the stabbing death of Cash App founder Bob Lee after a high-profile trial after 6 weeks of testimony and 7 days of deliberations.

Momeni will now face a sentence of 15 years to life in prison for second degree murder.

Momeni was originally charged with first-degree murder, but the lesser conviction means that while the jury found that he intentionally killed Lee, he did so without premeditation .

“In a world where the powerful and well-connected sometimes act as though they are immune to consequences, it is heartening to see a jury of ordinary San Franciscans demonstrate that if you break the law, you will be held accountable,” said Assistant District Attorneys Omid Talai and Dane Reinstedt in a press release .

Oliver Lee said that they would have preferred a first degree murder conviction but that justice was served. “We’re happy with the result today,” Oliver Lee said. “We’re happy that Nima Momeni will not be on the streets and no longer has the opportunity to harm anybody else in this world .

“This man deserves life in prison as far as I’m concerned,” Lee’s ex-wife Krista Lee said after the verdict was announced .

Momeni showed no visible emotion as the verdict was read. His mother, present in court, maintained her son’s innocence.

Fast Facts

• Date of murder: April 4, 2023 (2:35 AM)

• Victim: Bob Lee (43), Cash App founder, MobileCoin Chief Product Officer

• Accused/Convicted: Nima Momeni (38)

• Murder weapon: 7-inch Joseph Joseph kitchen knife from Khazar’s apartment

• Key evidence: DNA (99% match on knife handle, 98% on blade), surveillance footage, 911 call, text messages

• Trial verdict: Guilty of second-degree murder (December 17, 2024)

• Sentence: 15 years to life in prison

💡 Tip of the Week: When Self-Defense Claims Don’t Add Up: Reading Between the Lines of Testimony

Nima Momeni’s defense rested on a single claim: Bob Lee attacked him over a “bad joke” about strip clubs, and Momeni simply defended himself by redirecting the knife. But the jury didn’t buy it. Why?

Because self-defense claims must be consistent with ALL the evidence, not just the defendant’s version of events.

1. The “bad joke” motive made no sense. Prosecutor Omid Talai repeatedly hammered this point: why would Bob Lee, described by friends and colleagues as a “teddy bear” who was never aggressive even when intoxicated, suddenly try to kill someone over a comment about strip clubs? The motive didn’t match Lee’s character, and multiple witnesses testified that Lee was friendly and non-confrontational.

2. The knife came from Khazar’s kitchen. If Lee was the aggressor who “pulled a knife from his pocket,” why was the murder weapon a kitchen knife from the apartment they’d just left? This strongly suggested premeditation or at least that Momeni had armed himself before the confrontation.

3. Momeni’s behavior after the stabbing was suspicious. He threw the knife over a fence, drove away, and never called 911 or sought help for Lee. When his sister texted him asking what happened, he became evasive and threatening. These aren’t the actions of someone who acted in pure self-defense.

4. The surveillance footage contradicted his story. Video showed Momeni “suddenly moving toward” Lee, not the other way around. If Lee had been the aggressor, the body language and movement patterns would have looked different.

5. His testimony kept changing and contradicting other evidence. During cross-examination, Momeni interrupted the prosecutor repeatedly, refused to answer direct questions, and at one point even suggested “another person altogether” might have killed Lee. These inconsistencies damaged his credibility.

What this means for case analysis:

When evaluating a self-defense claim, ask these critical questions:

• Does the defendant’s story match their pre-attack behavior? If Momeni truly had no animosity toward Lee, why did he text his sister asking about “inappropriate” behavior and “drugs”? Why did surveillance show him arriving at the apartment hours before Lee?

• Is the motive for the alleged attack plausible? Would the victim really attack someone over the stated reason, given their known personality and behavior patterns?

• What did the defendant do immediately after? Call 911? Render aid? Or flee, dispose of evidence, and lie to loved ones?

• Does the physical evidence support the story? Wounds, DNA, surveillance footage, and forensic analysis can show who was the aggressor and who was defending themselves.

• Are there witnesses whose testimony contradicts the defendant? In this case, multiple people testified that Lee was never aggressive, even when high on drugs.

• The Momeni case teaches us: A self-defense claim isn’t just about who held the knife last. It’s about the totality of circumstances — motive, opportunity, behavior before and after, physical evidence, and whether the defendant’s story makes logical sense given everything else we know.

  Because when a “bad joke” becomes a murder weapon, it’s not self-defense. It’s just murder.

🧩 CASE CRACKERS: This Week’s Cipher Challenge

The DNA Dilemma: Momeni’s DNA was on the knife handle at a ratio of 1.66 septillion to 1, and Lee’s DNA was on the blade at 2.89 octillion to 1. Momeni claimed he only touched the knife to throw it away. Question: Why did the jury reject this explanation despite it being technically possible?

a) Because DNA transfer requires prolonged contact, not brief touching
b) Because the explanation was inconsistent with his self-defense story (why would he throw away evidence if he acted lawfully?)
c) Because the video showed him moving toward Lee, not defending himself

(Hint: Think about behavior, not just biology.)

Detective Insights - The Tech Elite’s Dark Side & the “Protective Brother” Defense

This case pulled back the curtain on San Francisco’s wealthy tech scene — a world where cocaine and ketamine flow freely at late-night parties, where married women have “casual sexual relationships” with tech moguls, and where a drug dealer named Jeremy Boivin is a regular at gatherings in luxury Millennium Tower apartments.

From an investigative standpoint, several patterns emerge:

1. The “Protective Brother” narrative vs. reality

Momeni’s defense tried to paint him as a concerned brother protecting his sister from harm. But text messages told a different story. After Lee’s death, when Khazar asked what happened, Momeni became threatening. The physical evidence was paired with testimony that called Momeni a “psycho” who put fear into his sister, who at one point threatened to call police if he didn’t explain what had happened to Lee .

A truly protective brother would have:

(1) Not blamed Lee for his sister’s choices, (2) Called the police about the alleged sexual assault, (3) Sought help for Lee after the stabbing, (4) Been honest with his sister about what happened.

Instead, Momeni’s “protection” manifested as rage, violence, and cover-up.

2. The drug-fueled timeline problem

Both Lee and Khazar were heavily intoxicated during the events leading up to the murder. Khazar testified she “didn’t even know what country she was in” when she called her brother for help. Yet Momeni expected Lee, who had cocaine, ketamine, and alcohol in his system, to be held accountable for “introducing” his sister to Boivin and for any alleged sexual assault that occurred.

This contradiction reveals Momeni’s real motive: misplaced rage. He couldn’t attack Boivin (the actual alleged assailant), so he redirected his anger toward Lee, who was easier to blame.

3. The surveillance camera blind spot

Video then shows the BMW drive to a “dark and secluded area” on Main Street, just out of view for the video to see the interaction between the two men .

This wasn’t random. Momeni drove to a location where the actual stabbing wouldn’t be captured on camera. But what he didn’t account for was that the video would show him “suddenly moving toward” Lee, contradicting his self-defense claim.

4. The text message that destroyed the motive

After Lee’s death, Khazar texted her brother: “Lol, you dumb f—k, Bob never touched me, No one did.”

This single message demolished the prosecution’s motive theory, but it also destroyed Momeni’s defense. If Lee hadn’t touched Khazar, why did Momeni stab him? The answer is clear: rage, control, and a violent response to perceived disrespect.

5. The “bad joke” that wasn’t

“To get out of it, I said what you could call a bad joke,” Momeni said on the stand. “I’d rather go hang out with my family rather than strip clubs,” he said he told Lee .

This “joke” was actually a judgment: Momeni was criticizing Lee’s lifestyle and implying he was a bad father for wanting to party instead of spending time with family. For someone already feeling judged about his sister, his lifestyle, and his behavior, this was likely the breaking point.

But Lee responding by “going from 0 to 100” and trying to kill Momeni over this comment? That narrative collapses under scrutiny.

From an investigative perspective, here’s what this case teaches us:

• Follow the digital trail. Text messages, surveillance footage, and phone records painted a timeline that contradicted Momeni’s testimony at every turn.

• Character evidence matters. When the defendant claims the victim was the aggressor, look at the victim’s history. Lee was consistently described as friendly, generous, and non-violent, even when intoxicated.

• The weapon’s origin is critical. A kitchen knife from the apartment they’d just left suggested premeditation or at least that Momeni had armed himself.

• Post-crime behavior reveals consciousness of guilt. Throwing away the murder weapon, fleeing the scene, becoming evasive and threatening with family members — these aren’t the actions of someone who acted in lawful self-defense.

• Wealth and status don’t prevent violence. This case involved tech elites, luxury apartments, and high-powered connections. But underneath the wealth was the same pattern seen in many homicides: jealousy, rage, and a need for control.

This case reminds us: When someone kills in “defense” of family honor, it’s not protection. It’s revenge disguised as righteousness.

🗣 Have Your Say – Help Shape What Solved Files Covers Next

We love hearing from our Case Crackers community, and your feedback helps us make each edition better than the last! This week, we want to ask you:

What content would you like to see more of in the newsletter?

Are there specific cases, topics, or mysteries you’d love us to explore?

Do you enjoy the mix of features we currently include, or is there something you think is missing?

Would you like more behind-the-scenes content, expert interviews, or interactive challenges?

Your input is invaluable, so don’t hesitate to share your thoughts! Drop us a reply or fill out this quick feedback form HERE. Together, we can make Solved Files your ultimate true crime resource.

Got another question or suggestion? Send it our way, and we might feature it in a future Q&A!

🔒 Step Inside the Evidence Vault

Every week in this newsletter, you get the key facts of each case. But there’s a side of true crime we can’t show here: raw photos, full reports, and uncensored evidence too sensitive for public release.

That’s why we built a private space for our most dedicated Case Crackers, on Patreon.

When you join, you’ll unlock:

📂 Exclusive crime scene and evidence photos — the same images investigators analyzed, including rare suspect and victim visuals.
🎥 Uncensored interrogation and footage access — the clips too intense or restricted to post publicly.
🕵 Behind-the-scenes breakdowns — discover how real detectives piece together motive, timeline, and truth.
💬 Community discussions — join other true crime enthusiasts to debate theories, spot clues, and share insights.

Here’s a small preview of what’s waiting inside:

And that’s just the beginning. Patreon members get full access to complete photo sets, classified-level case notes, and uncut footage that brings every investigation to life.

👉 Join Solved Files on Patreon today and step inside the vault of unfiltered true crime.

🕵 Stay Sharp, Stay Connected

While you wait for the next newsletter, keep your detective instincts sharp with our daily updates. On TikTok & Instagram, you’ll find crime polls that test your gut instincts, behind-the-scenes clues from our investigations, and bite-sized true crime drops you can watch anywhere.

And if you want to dig deeper, join us on Patreon for full trial timelines, extended case files, and uncut interviews you won’t see anywhere else.

Thanks for joining us on this week’s investigation. Every time you read, watch, or share, you help uncover what really happens when justice finally catches up to those who think they’ve gotten away. Until next time — stay observant, stay curious, and never stop asking questions.