MOUNTAIN VIEW (CBS ) — Police are trying to figure out how a killer made his way backstage at last night’s Wiz Khalifa show in Mountain View with a loaded gun.

The shooting happened Friday night backstage around 11 p.m. Police have not identified the 38-year-old man who was killed.

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Rap star Wiz Khalifa was onstage performing.

According to Mountain View Police Public Information Officer, Shino Tanaka, authorities don’t know the connection between the shooter and the victim, nor the connection to the concert goers, promoters or performers.

Usually only VIP’s are allowed behind the scenes and security is provided by the concert promoter.

“Generally [there is] a lot of security backstage,” said Tanaka. “We’re not sure how this occurred, we’re not sure how the firearm got to the backstage area, but we’re definitely going to follow this investigation.”

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Shoreline Amphitheatre issued a brief statement saying it was an isolated incident — and that it works closely with Mountain View police on security.

The suspect is described as a black man in his 20’s around 5’6″ to 5′ 8″. He was wearing mostly black clothing, with possibly white pants and a red baseball cap.

The concert was part of a national tour.

As word spread of the shooting — rapper Khalifa tweeted:

‘This was a senseless tragedy .. Violence is never the answer. My prayers go out to the victim’s family.’

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The Wiz Khalifa concert scheduled for Saturday night in Chula Vista, near San Diego, was canceled and will not be rescheduled.