MOUNTAIN VIEW, Calif. (KGO) -- People at last night's concert say a series of shots went off just as Wiz Khalifa was wrapping up his performance.
Friends and family say 38-year-old Eric Johnson was the victim.
Police say it all unfolded backstage.
"There generally is a lot of security back stage at concerts. We're not sure how this occurred. We're not sure how the firearm got to the backstage area," said Shino Tanaka of Mountain View Police.
Investigators held witnesses backstage for hours after the shooting, but the gunman somehow escaped.
"We don't handle security per se at the Shoreline Amphitheatre," said Tanaka.
Despite repeated requests for an interview - everyone from Live Nation and Shoreline Amphitheater declined. Instead a spokesperson said they are working closely with the Mountain View Police Department on this case and wouldn't offer any specifics about security backstage.
Friends and family of Eric Johnson are shocked that he was the victim, especially after reports that he may have been arguing with the gunman.
"He's not the arguing type, you know. He's a real smooth dude," said Frank Naborne.
Naborne is an Oakland based musician who had been working with Johnson's music company called "Full Pull Entertainment."
"I'm really like, shook up about his. I didn't just lose a person who was helping me build my career. I lost a friend," said Naborne.
Wiz Khalifa's concert in San Diego was cancelled today. He tweeted a brief statement about the shooting at the Shoreline.
"This was a senseless tragedy. Violence is never the answer. My prayers go out to the victim's family."
Investigators are looking for pictures or video of the gunman, and anyone who was with him.
Deadly shooting at Shoreline Amphitheatre raises backstage security questions