How did Cash App founder Bob Lee and stabbing suspect Nima Momeni know each other?

As Nima Momeni appeared Friday in San Francisco Superior Court to face a murder charge, the wider public is asking: How did he know Cash App founder Bob Lee? And why would he allegedly stab him to death earlier this month? 

The answers weren't immediately made clear, as his arraignment was continued to April 25.

Outside court, Momeni's attorney, Robert Canny, standing in for his sister, Paula Canny, refused to comment about the case. Momeni also declined a jailhouse interview, where he is being held without bail. 

Momeni appeared briefly, however, in the courtroom, making a heart sign to his sister, Khazar Momeni and her husband, Dr. Dino Elyassnia, a plastic surgeon. They made the heart sign back to him. 

At a news conference Thursday, San Francisco Police Chief Bill Scott would only say that the two knew each other.

But he did not say how.

"I can't say anything at this point," Scott told KTVU. 

In a brief interview by phone in Miami, Lee's former wife, Krista Lee, told KTVU that the name sounded familiar and she believes she had met Momeni's sister, but she didn't give out too many details. 

And she said she simply had no idea as why Momeni, 38, who owned his own IT company in Emeryville, would be charged with violently attacking her former husband, 43, with a knife at 2:30 a.m. on April 4.  

Many in the community – including Twitter's Elon Musk – had incorrectly believed that this was a random stabbing in a lawless city run amok.

But they were wrong.

At the news conference, Scott said that this stabbing had more to do with "human nature" than with the nature of San Francisco, or any city for that matter. 

The police chief added that the department had enough probable cause to arrest Momeni at his Emeryville business on Harlan Street, but was still "more work to be done." 

Most of Momeni's neighbors described him as generous and welcoming. They also said he liked cars, boats and liked to party. He also has a minor criminal record. He worked at Expand IT, which provides computer services to companies.

Sam Singer, a public relations expert, worked next to Momeni in the same building. The two visited each other's units and Singer said Momeni offered him IT help if he needed it. 

Singer said within the last month, there was a noise complaint in the building about a woman screaming Momeni's name in the hallway who couldn't find his apartment, but nothing came of it. 

Meanwhile, Lee was well respected in the tech world. 

He was the former chief technology officer of Square who helped launch Cash App. He later joined MobileCoin, a cryptocurrency and digital payments startup, in 2021 as its chief product officer.

His father, Rick Lee, wrote on Facebook that his son worked hard, was extremely smart and the type of person to "give you the shirt off his back." 

Krista Lee said her former husband had lived in Mill Valley but recently moved to Miami to live with his father after his mother died. 

She, like others, are waiting for Momeni's arraignment to learn more about why someone would take the life of a man she still loved. 

And while there are many questions that still remain, Krista Lee said at least their children will now have a little more "peace of mind." 

KTVU's Dave Detling contributed to this report.