Kyle Clark, of San Francisco, was taken into custody without incident at about 6:30 p.m. Tuesday near Seventh and Brannan streets, police spokesman Officer Albie Esparza said.
Esparza said the victim, a 35-year-old man, witnessed Clark and a young woman who was with Clark arguing at the back of a 29-Sunset bus at about 7:40 p.m. Monday.
After Clark allegedly slapped the woman, the victim tried to intervene and was stabbed multiple times in the torso, Esparza said.
Clark and the woman got off the bus at the next stop, and the victim got off at the stop after that, at Yorba Street and Sunset Boulevard, where he realized he had been stabbed.
The victim’s wounds were not life-threatening, Esparza said.
Police reviewed video surveillance from the bus as part of the investigation.
“Investigative leads led to the identification of the suspect,” Esparza said.
Clark was booked into San Francisco County Jail on suspicion of assault with a deadly weapon and battery causing serious bodily injury, according to the sheriff’s department. He is being held on $90,000 bail.