The forewoman reported in open court that the jury did, in fact reach a verdict of not guilty on both murder charges but they were deadlocked on the lesser charges.
From the dissenting opinion:
The forewoman reported that the jury had not voted on negligent homicide because the jurors “couldn’t get past the manslaughter” count on which they were deadlocked. Id., at 65.
In this context, the forewoman’s announcement in open court that the jury was “unanimous against” conviction on capital and first-degree murder, id., at 64–65, was an acquittal for double jeopardy purposes.2 Per Arkansas law, the jury’s determination of reasonable doubt as to those offenses was an acquittal “in essence.” Hughes, 347 Ark., at 707, 66 S. W. 3d, at 651. By deciding that the State “had failed to come forward with sufficient proof,”the jury resolved the charges of capital and first-degree murder adversely to the State. Burks, 437 U. S., at 10. That acquittal cannot be reconsidered without putting Blueford twice in jeopardy.