If they charge him and he pleads not guilty, then no, they don't have to prove a case.
But you don't charge someone unless you think you can prove the case, because you don't know if they will plead guilty.
On the other hand lots of people claim they have been coerced into pleady guilty to lesser charges because they were being "railroaded" on more serious charges.
Don't know how often that happens in real life, but doubt it could happen in such a high profile case.
If he is part of an international cartel of pedophile child porn traders I expect him to stop breathing soon after reaching the U.S.
INTERESTING! Hadn't thought of that wonder if that's what happened to the guy they found dead that "shot himself"? Last name began with H. Can't remember the rest.