The State Supreme Court in Mecham faced an unusual DUI circumstance.   In Mecham the driver was wanted on a warrant.  The officer who stopped Mecham driving, promptly arrested him and read him his Miranda rights.  Shortly after, the officer smelled alcohol, noted the watery/bloodshot eyes, and signs of impairment.   Suspecting DUI, the officer asked the driver to perform FSTs.  The driver refused.  The officer obtained a warrant for blood and the test showed the driver had a .05 BAC three-hours after his arrest.  At trial, the prosecution argued the reason the driver refused was because he knew that performing these tests would show he was impaired.  Mecham was convicted and appealed.

The question in Mecham was whether the refusal to cooperate with FSTs after arrest could be used against the driver.  The legal analysis was whether FSTs invade a privacy interest under the State constitution or are an unreasonable search under the Federal Constitution.   

The lead opinion (4 votes) concluded FSTs do not invade a privacy interest under the state constitution and are not a search under the Federal.  That means FSTs are not constitutionally protected and the prosecutor can refer to them for whatever value them might provide in the DUI case--including consciousness-of-guilt.   

Justice Fairhurst partly joined in the lead opinion, agreeing that FSTs done before arrest are not a search.  Since this is the majority of DUI cases, this agreement is important.  However, that circumstance is not this case, so the statement is dicta and does not control future cases.   What controls is Justice Fairhurst's conclusion that the officer was not permitted to do FSTs after arrest.   Her reasoning is that the Terry exception does not apply after arrest.   That means she votes to reverse.

The justices favoring reversal (4 votes) were in two camps.  One camp argued FSTs are a search that required either a warrant or an exception to the warrant requirement.  (No discussion on the search incident to arrest option).  The other camp thought the constitutional versus common-law basis for the right to refuse here was overly technical.  They focused on the fact the officer told the driver the FSTs are "voluntary" and concluded this was misleading if it could be used against the driver at trial.  The opinion did not discuss the impact of the Miranda warning provided to Mecham, or why that warning was ineffective. 

Counting up votes, there were 4 for affirming the conviction, and five to reverse.  Yet the opinion says it affirms the conviction.   I'm guessing the defense moves for a re-count.  No matter the outcome, expect more litigation on FST issues.  

The full opinion is here: State v. Mecham