Ellington, Justice. Antonio Randall stands accused in the State Court of Athens-Clarke County of driving under the influence of alcohol to the extent that it was less safe for him to drive, OCGA § 40-6-391 (a) (1), and other traffic offenses. The trial court granted Randall’s motion to suppress evidence of his refusal to submit to a warrantless blood test on the ground that Georgia’s Implied Consent statutes violate a DUI defendant’s due process rights by allowing blood test refusal evidence to be admitted against the defendant at trial. The State appealed.[1] On appeal, the parties are in agreement that the evidence is admissible for the limited purpose of explaining the absence of evidence of blood test results. Consequently, it was not necessary for the trial court to consider in this case whether admitting blood test refusal evidence for other purposes against DUI defendants is constitutional. Because a trial court should consider a challenge to the constitutionality of a statute only when necessary to resolve the merits of the case at bar, we vacate the trial court’s order granting Randall’s motion to suppress. The material facts, as developed at the hearing on Randall’s motion to suppress, are undisputed. On April 6, 2021, an Athens- Clarke County police officer initiated a traffic stop after observing Randall’s vehicle failing to maintain its lane while traveling on College Station Road. During the traffic stop, the officer smelled the odor of alcohol when Randall spoke to him and observed that Randall had glassy eyes and difficulty with balance when he exited the vehicle. The officer arrested Randall for DUI, read Randall the statutory Implied Consent notice for drivers aged 21 years and over,[2] and requested that Randall submit to a blood test. Randall refused to submit to a blood test, and no test was performed. In Randall’s brief in support of his motion to suppress in the trial court, he argued that using a defendant’s exercise of his right to refuse a warrantless search against him at trial as evidence of consciousness of guilt constitutes punishment for exercising a plainly available constitutional right and thereby violates a defendant’s due process rights under the United States Constitution and the Georgia Constitution. After a hearing, the trial court granted in part Randall’s motion to suppress and excluded any evidence of his refusal to consent to the requested blood test.[3] The trial court reasoned that, to the extent that OCGA § 40-5-67.1 informs a person that refusing to submit to blood testing may be offered as evidence against them at trial, it needlessly and unnecessarily chills a defendant’s exercise of the constitutional right to refuse a warrantless search. To the extent that OCGA § 40-6-392 (d) allows that evidence to be admitted at trial, it impermissibly and unduly burdens a defendant’s exercise of the right to refuse warrantless blood testing. Therefore, to that extent, OCGA § 40-5-67.1 and OCGA § 40-6-392 (d) violate a defendant’s due process rights guaranteed by both the United States and Georgia Constitutions.[[4]] 1. On the admissibility of blood test refusal evidence, the State asserts on appeal that the public is broadly aware of DUI investigation procedures and expects that blood alcohol testing is done in every DUI case. The State maintains that its purpose in introducing evidence that Randall refused a blood test is to explain to the jury why the State is not offering test results into evidence.[5] Randall, on the other hand, challenges the admissibility of test refusal evidence broadly as substantive evidence of guilt, that is, evidence of “guilty knowledge” and “consciousness of guilt.” In Randall’s brief on appeal, he states that he does not argue that all evidentiary consequences of refusing a blood test are unconstitutional, pointing to a Virginia statute providing that a DUI suspect’s unreasonable refusal to permit a blood or breath test shall be admissible into evidence for the sole purpose of explaining the absence at trial of a chemical test and not as evidence of the defendant’s guilt.[6] “Properly enacted statutes carry a presumption of constitutional validity, and inquiry into the constitutionality of a statute generally should not be made by the trial courts if a decision on the merits can be reached without doing so.” State v. Brannan, 267 Ga. 315, 317 (477 SE2d 575) (1996). Here, the parties’ briefing in the trial court led the trial court to issue a ruling on the merits of Randall’s argument that, to the extent that OCGA §§ 40-5-67.1 (b) and 40-6-392 (d) allow for the introduction of evidence against an accused in a DUI prosecution, they violate state and federal due process guarantees. But clarification of the parties’ positions in appellate argument has made the constitutional ruling by the trial court on the admissibility of blood test refusal evidence unnecessary. The trial court’s order is vacated in this respect. We emphasize that, in vacating the trial court’s ruling in this case, we express no opinion about the important and difficult constitutional questions that remain unresolved. Through these proceedings, the State has restricted itself to using refusal evidence in this case only for the limited purpose of explaining the absence of test results. Thus, the State may not seek a jury instruction authorizing the jury to draw any other inference from Randall’s blood test refusal.[7] Whether Randall will wish to have the jury instructed regarding the limited purpose for which refusal evidence is admitted is an issue the trial court will take up at the proper time. 2. As noted above, in addition to ruling on the constitutionality of admitting blood test refusal evidence against a defendant, the trial court ruled that, to the extent that the Implied Consent notices set out in OCGA § 40-5-67.1 (b) inform a person that refusing to submit to blood testing may be offered as evidence against him at trial, OCGA § 40-5-67.1 (b) needlessly and unnecessarily chills a defendant’s exercise of the constitutional right to refuse a warrantless search.[8] Although Randall challenged the constitutionality of OCGA § 40-5-67.1 (b) in the trial court on the grounds that allowing admission of his refusal to submit to the blood test to show consciousness of guilt violated his constitutional rights, see Division 1, supra, Randall did not challenge the statute on the basis that the text of the Implied Consent notices chill a defendant’s exercise of the constitutional right to refuse a warrantless search. The trial court should not have expanded the scope of its review of the constitutionality of the statute, beyond that raised by the challenger himself. See Brannan, 267 Ga. at 317. Accordingly, the trial court’s ruling on that issue is also vacated. Judgment vacated. All the Justices concur.
