jury trial, appellant Mellecia Spencer was convicted of one
count of driving under the influence of alcohol (less safe)
and one count of possession of an open container. She
appealed the judgment of conviction and sentence only as to
the conviction for DUI. The Court of Appeals affirmed her
conviction in Spencer v. State, 337 Ga.App. 360 (787
S.E.2d 320) (2016) (Spencer I). We granted this
petition for certiorari to consider whether the Court of
Appeals erred in holding that the trial court properly
admitted a police officer's testimony correlating the
results of a horizontal gaze nystagmus ("HGN") test
with a numeric blood alcohol content or "BAC".
Because this testimony was admitted without a sufficient
foundation having been laid under Harper v. State,
249 Ga. 519 (292 S.E.2d 389) (1982), we reverse the judgment
of conviction and sentence with respect to the DUI.
underlying facts are laid out in detail in Spencer
I. In brief, Spencer was stopped for a nonworking
headlight, and the investigating officer noted her slurred
speech, an odor of alcoholic beverage, a wristband from a
bar, and a plastic cup in the center console that appeared to
contain an alcoholic drink. The officer administered the HGN
test to Spencer, who exhibited 4 out of 6 "clues"
trial, the officer was questioned by the solicitor regarding
the HGN test:
Q: Just based on your training and experience, have you
noticed a correlation between four out of six clues on the
HGN test that you perform in the field and a blood alcohol or
breath alcohol content that would be in a person's
A: Based on my training and my experience, four out of six
clues generally indicates a blood alcohol level equal to or
greater than a .08.
objected to this testimony and, after a lengthy colloquy, the
trial court overruled the objection. The solicitor questioned
the officer again:
Q: Is there a correlation between what you saw on the HGN
test and, in general, a person's alcohol content level on
A: Based off my training and my experience, generally there
Q: And what is that correlation?
A: Generally, the four out of six clues indicates an alcohol
concentration equal to or greater than a .08.
found Spencer guilty, the trial court denied her motion for
new trial, and she appealed, contending inter alia that the
trial court erred in allowing this testimony. The Court of
Appeals affirmed her conviction, holding:
[I]t is true that an arresting officer's testimony
identifying a specific numeric blood alcohol content based
solely on a defendant's HGN results should be excluded.
But the officer here did not give such testimony. Rather, he
testified that in performing the test he looks for up to six
clues in a subject's eyes, that observing four or more
clues indicates impairment due to alcohol, and that four out
of six clues generally indicates a blood alcohol level equal
to or greater than .08.
(Citations and punctuation omitted.) Spencer I, 337
Ga.App. at 360-361 (1). The court held that, because the
officer did not identify a specific blood alcohol level for
Spencer, but merely testified that a finding of four out of
six clues generally exceeds the impairing level of .08, the
trial court did not err in allowing the testimony.
Id. at 361 ...