Michael White, accused of fatally stabbing real estate developer Sean Schellenger near Rittenhouse Square last year, testified Tuesday that in the moments before Schellenger tried to tackle him during a spontaneous encounter, he told White: “I’m going to beat the black off you.”

In his first public remarks on the stabbing, White, 22, told jurors at his voluntary-manslaughter trial that Schellenger’s comment was the second time in just a few seconds that he had seen or heard Schellenger or his friends utter racial remarks during a traffic dispute at 17th and Chancellor Streets in July 2018.

Speaking largely in a monotone during testimony that lasted several hours, White said he was afraid for his safety when Schellenger, 37, began approaching him and hurled the racial remark at him. He said he pulled out a knife to try to scare Schellenger off, then used it in self-defense as Schellenger — whom he described as red-faced and aggressive — sought to take him to the ground.

“I wasn’t trying to kill nobody,” White said. “I was trying to get him off me.”

White’s account of the killing is a key moment in his trial, at which prosecutors have been seeking to prove that he unnecessarily inserted himself into a situation that did not involve him and killed a man he did not know.

White and his attorneys have argued self-defense, saying Schellenger had initiated the physical contact and White was afraid of being injured or killed.

In many ways, White’s recollection of events mirrored what other witnesses said during two previous days of testimony.

Still, his version included one significant difference: He is the only person who said Schellenger or his friends used racist language during the incident.

The case has attracted wide interest and stoked racial tensions almost since it occurred. It also has generated controversy, with Schellenger’s relatives criticizing District Attorney Larry Krasner for downgrading charges from first-degree murder after White’s arrest to voluntary manslaughter just before trial.

White has been free on bail since last fall, when Krasner first modified the charges against him. He has betrayed little emotion during the trial, at which supporters of both White and Schellenger have packed one of the larger courtrooms in the Stout Center for Criminal Justice.

White spent about three hours on the stand Tuesday, first answering questions from one of his lawyers, chief city defender Keir Bradford-Grey, then under cross-examination from Assistant District Attorney Anthony Voci.

White told jurors he had been working as a bicycle food courier on the night of July 12, 2018, when he stopped his bike on 17th Street because a Mercedes-Benz on Chancellor had blocked his path at the corner.

One of the men inside the car, Uri Jacobson, told White, “‘Sorry, bud, my friends and I have been drinking tonight,’” White testified.

White said he then witnessed the driver of the Mercedes, Norris Jordan — Schellenger’s friend and the co-owner of the restaurants Lou Bird’s and Happy Rooster — honking his horn at a Ford Taurus stopped in front of his car. After the honking stopped, White said, he read Jordan’s lips and saw him mouth a racial slur about people in the Taurus, who were black.

Jordan had vehemently denied that allegation when he was questioned on the witness stand last week.

White said Schellenger then got out of the Mercedes and appeared as if he wanted to confront the people in the Taurus. White said “something didn’t feel right,” so he told Schellenger, “You don’t have to be a tough guy” in an attempt to defuse the situation.

The driver of the Taurus told White everything was OK, White testified, but shortly afterward, White said he was confronted by Schellenger, whom he described as red-faced with his fists clenched and teeth gritted.

White said Schellenger told him, “‘I’m going to beat the black off you’” while moving toward him. No one else has testified to hearing Schellenger say those words.

White said he pulled out a knife from his backpack and told Schellenger to back up. He said Schellenger then charged at him, and he stuck the knife in Schellenger’s back while being lifted from the ground.

“I was trying to get him off me,” White said, describing the encounter as having happened in “the blink of an eye."

The two men tumbled to the ground together, and the knife went several inches into Schellenger’s torso. White, under questioning by Voci, suggested that Schellenger’s fall may have deepened the wound, saying he did not have the strength or leverage to cause it himself.

“I did not drive that knife that far into his back,” White said.

Cell-phone video made by a witness to the stabbing, played during the trial, showed White pulling the weapon out of Schellenger’s back and running away. He testified that he took a train back to West Philadelphia, where he threw the knife onto the roof of a house.

He turned himself in to police the next day and later told authorities where to find the knife.

White said Tuesday that he had run because he was in shock and scared.

“I couldn’t believe what had just happened,” he said.

Voci also questioned White about a note he had written on his cell phone nine days before the killing, which, according to testimony, read: “This ain’t like me, nah. Don’t piss me off, you’ll get cut,” punctuated with profanity.

Voci sought to point out through his questions that White wrote the note around the same time he said he had started to carry the knife. White, who previously competed in slam poetry competitions, said that he frequently wrote down incomplete thoughts on his phone, and that the note was not a reference to the knife or to thinking about using it.

Other witnesses who testified Tuesday included a woman from Jacksonville, Fla., called by White’s defense lawyers, who testified that she had seen Schellenger initiate a fight with bar bouncers in Destin, Fla., in 2008.

Meanwhile, a toxicology expert called by White’s defense lawyers told jurors that he believed that a medical examiner’s report issued after Schellenger’s death showed he may have used cocaine just hours before encountering White.

Closing arguments were expected to begin Wednesday morning, and jurors could begin deliberating by the afternoon.