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WASHINGTON -- Police found several weapons stashed in a Metro station as they investigated a fatal stabbing.

According to court documents, crime scene investigators found a gun behind a locker on the north end of the Woodley Park platform, a bloody knife on top of a pylon and another knife hidden in a phone booth at the other end. All the items are believed to have been placed in the seconds after 18-year-old Olijawon Griffin was stabbed to death on the mezzanine platform early on Nov. 17.

The Woodley Park Metro station exits on Connecticut Avenue, leading to the National Zoo.

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Prosecutors describe the murder as the result of a chain of robbery and violence that began as what one witness described as a setup to steal Griffin's expensive Helly Hansen jacket, which can retail for $300.

The nine suspects arrested ranged in age from 15 to 17. Only one was originally charged as an adult, but juvenile charges were dropped against four defendants, all 17, on Monday and they were charged as adults with armed robbery.