William J. Brennan, Jr., Grady v. Corbin — Opinion of the Court
“ Thus, a subsequent prosecution must do more than merely survive the Blockburger test. As we suggested in Vitale, the Double Jeopardy Clause bars any subsequent prosecution in which the government, to establish an essential element of an offense charged in that prosecution, will prove conduct that constitutes an offense for which the defendant has already been prosecuted. [11] This is not an "actual evidence" or "same evidence" test. [12] The critical inquiry is what conduct the State will prove, not the evidence the State will use to prove that conduct. ”
