What is the test for determining whether a jury can agree on a verdict in a driving under the influence case?

^7. The exception is Commonwealth v. Broomhead (Mass.App.Ct. 2006) 855 N.E.2d 413, a driving under the influence case. The court reversed for violation of a state rule of criminal procedure. (Id. at p. 417.) There the court did conclude the case was a close one, because two previous juries had hung and the final jury had sent out a note asking what would happen if it could not agree on a verdict. (Id. at p. 420.) The case does not reveal how the previous juries were divided, nor does it discuss the possible differences in evidence or theories presented. The paucity of information makes it difficult to evaluate whatever persuasive value the case may have.