What is the burden of proof at a VOP hearing?

The State must show it is more likely than not that a violation occurred. That's a meaningfully lower bar than beyond a reasonable doubt, and it's why violation hearings are harder to win than trials.

Two features soften it somewhat.

Willful and substantial. A violation must be both. A technical failure that was not willful, or that was minor in the context of overall compliance, does not automatically support revocation. That's an argument distinct from disputing the facts.

The hearsay limit. Hearsay is admissible at these hearings, but it generally cannot be the sole basis for revocation. Where the State's case is entirely a report, a document, or an officer relaying what someone else said, that limitation matters and should be raised.

Also worth knowing: an acquittal on a new criminal charge does not necessarily prevent a violation based on the same conduct, because the standards differ. Those proceedings run independently.