Deshon Marman, 20, a student at the University of New Mexico, may be charged with trespassing, battery and resisting arrest, the San Francisco Chronicle reported.
Marman, a native of San Francisco, was a close friend and former teammate of David Henderson, who died 11 days after he was shot May 26. He spoke at Henderson's funeral.
Police Sgt. Michael Rodriguez said Marman, boarding a plane Wednesday for his return to New Mexico, refused a request from a US Airways employee to pull up his pants. Police had been called with a complaint of indecent exposure from someone who said a man's pants were so low most of his boxer shorts were visible.
Donna Doyle, Marman's mother, said he had been upset by Henderson's death and the funeral. She suggested he became a target at the airport because of his race, clothes and dreadlocks.
"But he's a good kid trying to make it, and he's going through a lot," she said. "And then this happens."
Bail was set at $11,000.