GLaDOS and Wheatley were put in hoofcuffs, and were guarded by three guards each.
"Everypony sit down." Celestia ordered. They all obeyed. "Earlier today, Canterlot Castle was blown to pieces. Care to explain how that happened?" GLaDOS glanced around nervously.
"HE DID IT!" She pointed an accusing hoof at Wheatley.
"I meant the truth." Celestia told her.
"I did it..." GLaDOS said quietly.
"And why?
"Because I like being in charge..."
"And that meant you had to blow up Canterlot Castle?"
"Yes...." Celestia glared at her.
"5,000 ponies died in that explosion. I just want you to think on that."
"Cool! I mean- That's too bad..."
"Princess, I know GLaDOS deserves to be punished, but what did Wheatley do?" Scootaloo inquired.
"I'm glad you asked. Wheatley, is it true that you beat one of the guards with a brick because he called you a moron?" Celestia asked him.
"I refuse to answer that." He told her.
"Oh really?" Trollestia.
"Uh huh."
"Captain Ironside, can you please give me that Taser? Thanks." Followed by a lot of yelling.
"OKAY YES I DID DO IT!" Wheatley confessed.
"Thank you for cooperating." Celestia told him. "And I think I know what to do with you" *Evil grin*