Regardless of how long you stay in the U.S., even just for a layover, you will be required to go through U.S. Customs just the same as if the U.S. was your final destination. If your criminal record is discovered, you could be barred from entry, arrested on the spot, detained at the border and/or face confiscation of personal property in your possession, whether or not the property is yours. This could mean you will not make your travel connections and your entire trip could be jeopardized.
For more travelers, it is not worth the risk. See if you qualify for a U.S. Entry Waiver or Schedule a call to get started on your U.S. Waiver application.