Tech consultant Nima Momeni pleaded not guilty Thursday to a murder charge in the stabbing death of Cash App founder Bob Lee on the streets of San Francisco.

San Francisco Superior Court Judge Victor Hwang ordered Momeni, 38, kept in jail without bail, saying he posed a public safety risk if released. Momeni, who appeared in an orange sweatshirt and pants, did not speak, and his attorney Paula Canny entered the plea on his behalf.

The case has drawn national attention, partly given Lee’s status in the tech world. Lee was found with three stab wounds, including one to the heart, shortly after 2:30 a.m. April 4 and was taken to a hospital where he later died. He was found in the Rincon Hill neighborhood in downtown San Francisco, which has tech offices and condominiums but little activity in the early morning hours.

Lee, 43, created Cash App, a mobile payment service, and was the chief product officer of the cryptocurrency MobileCoin. He was mourned as a loving father of two who made friends wherever he went.

Prosecutors have not provided a motive but say Momeni stabbed Lee after a dispute related to Momeni’s sister, who appeared in court Thursday alongside their mother.

Assistant District Attorney Omid Talai argued Thursday to detain Momeni without bail, saying that the defendant drove Lee to a secluded spot and used a knife that was part of a unique kitchen set belonging to his sister. Police recovered a knife with a 4-inch (10-centimeter) blade at the scene.

Talai said that analysis showed Momeni’s DNA on the handle of the knife and Lee’s DNA on the bloody blade and no evidence that Lee had touched the handle, contradicting Canny’s claim of self-defense for her client.

But Canny said that Momeni did not drive Lee to a secluded spot with the aim of killing him. Instead, she said, Lee directed him to pull over after calling an Uber because the two had argued. The last time Momeni saw Lee, Canny said, Lee was standing upright and walking away.