Nima Momeni, the 38-year-old Silicon Valley outsourcer accused of fatally stabbing Cash App founder Bob Lee in April, pleaded not guilty to murder Thursday.

The judge did not set bail, and Momeni will remain in custody. The court is expected to schedule a preliminary hearing Friday morning.

The suspect did not speak during the proceedings. His lawyer said outside of court that the incident had been an accident and self-defense.

Momeni, an Iranian national, was arrested on April 13, nine days after allegedly knifing the 43-year-old tech titan in a dispute over his sister, Khazar Momeni, the wife of a prominent San Francisco plastic surgeon.

CASH APP FOUNDER BOB LEE'S SAN FRANCISCO STABBING LINKED TO ‘SEX AND DRUGS’ PARTY LIFESTYLE: REPORT

Momeni Lee split

Nima Momeni, left, is jailed in San Francisco on a murder charge in the stabbing death of Cash App founder Bob Lee. San Francisco police say the two knew each other. (Nima Momeni/LinkedIn, Bob Lee/Facebook)

She was in court for Thursday's arraignment, as were the friends and family of Bob Lee.

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.

CASH APP'S BOB LEE VISITED SUSPECT'S SISTER HOURS BEFORE MURDER. ARGUED WITH ALLEGED KILLER, COURT DOCS REVEAL

Khazar Momeni inset Bob Lee

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)

Later that evening, the two were seen on surveillance video leaving an apartment building together and getting into Momeni's car.

They drove to a parking lot, where court documents allege Lee was stabbed through the heart with a kitchen knife and seen stumbling down Main Street in San Francisco's Rincon Hill neighborhood, where he begged passersby for help and called 911 himself. 

Nima Momeni appears before judge, accused of the stabbing murder of Cash App founder Bob Lee in San Francisco

Heart symbols are exchanged between Nima Momeni, the 38-year-old founder of software company Expand IT, and family members as he appears before Judge Christine Van Aken, accused of the stabbing murder of Cash App founder Bob Lee in a courtroom sketch in San Francisco, California, April 14, 2023. Judge Van Aken ordered that Momeni be portrayed in sketches as unidentifiable to the public and jury pool.  (REUTERS/Vicki Behringer)

In court Thursday, lawyers revealed the knife had come from Khazar Momeni's kitchen and allegedly had her brother's DNA on it along with Lee's blood.

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.

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Momeni's arraignment had previously been postponed because his attorney, Paula Canny, had been out of town at the time of his arrest.