In a DUI investigation, it is crucial for both the state and the defendant to gather evidence relevant to intoxication close in time to when the defendant allegedly committed the crime. Otherwise, any alcohol that may have been in the blood will have decomposed before the blood can be tested. McNutt v. Superior Court, 133 Ariz. 7, 10 n.2, 648 P.2d 122, 125 n.2 (1982).
In view of the evanescent nature of alcohol in the bloodstream, such evidence may include not only chemical or other scientific evidence, such as a blood or breath test, McNutt, but also other forms of potentially exculpatory evidence, such as observations by "non-police witnesses" of a suspect's physical appearance and function.
State ex rel. Webb v. City Court, 25 Ariz. App. 214, 216, 542 P.2d 407, 409 (1975). See also United States v. Canane, 622 F. Supp. 279, 281 (W.D.N.C. 1985) (recognizing need for suspect's "access to his counsel, friends, relatives, or some disinterested person within a relatively short time after his arrest").
Thus, a DUI suspect has a qualified due process right to gather independent evidence of sobriety while it still exists, so long as exercise of that right does not unduly delay or interfere with the law enforcement investigation. See Kunzler; Holland; Webb. See also State v. Montano, 149 Ariz. 385, 389, 719 P.2d 271, 275 (1986).
And, "the right to counsel is an extension of the doctrine that defendants have the right to gather independent exculpatory evidence." State v. Transon, 186 Ariz. 482, 485, 924 P.2d 486, 489 (App. 1996).
As the court noted in State v. Carr, 128 Idaho 181, 911 P.2d 774, 777-78 (Idaho App. 1995):
The person contacted by the arrestee could arrange for a photograph to be taken to demonstrate that the arrestee's eyes were not bloodshot but were clear and white; prepare a tape recording to demonstrate that the arrestee had clear speech; videotape the arrestee to show that he or she has balance and is able to walk in a straight line; perform a gaze nystagmus test to show smooth eye pursuit at all angles; or simply serve as a witness who observed the aforementioned characteristics of sobriety.
When the state unreasonably interferes with a DUI suspect's ability "to attempt to gather evidence exculpating him on the issue of intoxication," "dismissal of the case with prejudice is the appropriate remedy because the state's action foreclosed a fair trial by preventing the defendant from collecting exculpatory evidence no longer available." McNutt, 133 Ariz. at 10, 648 P.2d at 125. See also Keyonnie, 181 Ariz. at 487, 892 P.2d at 207. Our supreme court has explained why dismissal is appropriate under such circumstances: