Suspect in killing of Cash App founder Bob Lee to be arraigned

The suspect in the killing of 43-year-old Cash App founder Bob Lee is set to be arraigned in a San Francisco courtroom on Tuesday.

The suspect, Nima Momeni, is the owner of an Emeryville, California-based company called Expand IT. He was arrested earlier this month and charged with murder.

Momeni allegedly drove Lee to a dark, secluded area and stabbed him three times, according to a motion filed by prosecutors earlier this month.

Lee, an executive at Cryptocurrency firm MobileCoin, was killed in the early morning hours on April 4 in the San Francisco neighborhood of Rincon Hill, the San Francisco Police Department said.

The doctor who conducted the autopsy found that Lee had been stabbed three times, including one strike that penetrated his heart, the motion said.

Police later found a roughly 4-inch blade at the scene that appeared to have blood on it, the document said.

During the previous afternoon, Lee spent time with Momeni's sister and a witness, who identified him or herself as a close friend of Lee, prosecutors said.

Later in the day, at Lee's hotel room, he had a conversation with Momeni in which he asked Lee about whether his sister was "doing ... anything inappropriate," the witness told the police, according to the document.

Lee reassured Momeni that nothing inappropriate had taken place, the witness said to police.

Early the following morning, at about 2 a.m., camera footage showed Lee and Momeni leaving Lee's hotel and getting into Momeni's car, a BMW Z4, prosecutors said.

Video shows the BMW drive to a secluded and dark area where the two men got out of the car. Momeni "moved toward" Lee and the BMW drove away from the scene at high speed, according to the court document.

In a separate incident, Momeni was accused of assaulting a woman in August, according to an Emeryville Police Department report obtained by ABC News.

On Aug. 1, officers responded to a caller who said she was inside a unit with Momeni when he grabbed her arm, pulled it and pushed her, the report said.

Momeni was cited in that case.

"Mr. Momeni was taken into custody without incident in Emeryville and transported to San Francisco County jail and booked on a charge of murder," San Francisco Police Chief William Scott said earlier this month.

"Our investigators have been working tirelessly to make this arrest," Scott added.

London Breed, the mayor of San Francisco, said in a statement to ABC News earlier this month that Lee's death marks a "horrible tragedy."

"Bob's dream was to make Technology free and available," Timothy Oliver Lee, Bob Lee's brother, said in a statement after the incident.

"He positively affected millions of people throughout his life. He had an overarching need to make Technology accessible, and to help out everyone."