In this context, I would recommend translating "Попался" with "You're busted!" or simply "Busted!", although this is a bit slangy. Another example: "The cops busted a drug lab," meaning that the police raided a narcotics laboratory and arrested everybody. Another possibility is "Gotcha!" (a phonetic corruption of "I've got you!"), which is very colloquial doesn't sound as slangy as "Busted!"
I'm not sure about the best translation of "Вспотел?" -- could you explain the context? (Mainly, I want to know if it refers to "exercise sweat" or "nervous sweat".)