It's the deadliest miltary workplace shooting since the 2009 mass shooting at Fort Hood that killed 13, so Monday's Washington Navy Yard massacre raises the question again: how could this happen at a military installation in the U.S.
CNN's Barbara Starr reports.
Many of the security measures at the Navy yard are similar to other bases. Captain Mark Vandross spelled out security procedures to CNN's Wolf Blitzer:
"You present credentials, your D.O.D. common access card, to an armed security guard who then clears you on to the base. Then to get into building 197, there's armed security at the door of the building."
And he says contractors are also scrutinized:
"You go past armed security guards and then your credentials are computer-read and there's a kiosk you go through and it gives you a green light or red light but the green light shows your credentials are recognized as someone who is supposed to be in that building."
Former Navy Commander Kirk Lippold weighs in on the issue of security clearances after Monday's shooting.
He says, "the pattern of misconduct more than anything else is what concerns me, cause clearly you have a documented case where this individual misbehaved, the Navy knew it, and yet still when he got out, he was allowed to get a clearance.”
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