From Halopedia, the Halo wiki
Jasper Arko was a human who listened to Benjamin Giraud's Hunt the Truth audio journal in 2558. After Giraud's entries claimed the Master Chief was the product of covert supersoldier experiments, Arko mailed Giraud an audio email where he claimed Giraud was doing the right thing. He felt that humanity deserved to know the truth behind the propaganda the UNSC had told them, and expressed horror at the revelation of where the Spartan came from.
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