The day after the final battle, Severus Snape materialized at the very doors of the Ministry to turn himself in. This caused no small embarrassment to the Auror division, which had been hunting him nonstop for the past year. The Minister claimed that the Aurors' fearsome reputation was the cause, but no one was fooled.
Wizarding publications and politicians were elated, having found their whipping boy. Snape, they said, was the epitome of all that was evil. Any whispers to the contrary were swiftly squelched.
During trial, Snape pled guilty to the murder of Albus Dumbledore. He offered no defense of any kind. When questioned as to his motives, he merely stated, "I did what was asked of me."
It was only after his execution, when Dumbledore's Pensieve was recovered, that the world learned just whose orders they had been.