State v. Herrera, 823 S.E.2d 923

Herrera was arrested after claiming a package containing six bags of suspected marijuana; indicted for trafficking in marijuana between ten and 100 pounds.
The State sought to qualify Detective Jared Hunnicutt as an expert; Hunnicutt had police experience and one SLED course but no prior General Sessions qualification as a marijuana analyst.
The trial court hesitated but ultimately qualified Hunnicutt narrowly to testify only on identification (whether the substance was marijuana).
Despite that limitation, the State elicited from Hunnicutt testimony about analysis and the weight of the marijuana; Herrera objected that Hunnicutt was unqualified to testify about testing or weight.
Hunnicutt had not calibrated the Greenwood County scale, relied on belief someone else calibrated it, and weighed an empty bag from the sheriff’s office (not any of the six seized bags) and assumed similar weights; the total reported weight was 10 lbs 2.78 oz — just over the trafficking threshold.
The court of appeals affirmed; the supreme court granted certiorari and reversed, holding admission of Hunnicutt’s weight testimony was an abuse of discretion and remanding for a new trial.

Issue	Plaintiff's Argument (Herrera)	Defendant's Argument (State)	Held
Whether Hunnicutt could be qualified as an expert in marijuana identification	Hunnicutt lacked sufficient training/experience to be an expert	Hunnicutt's policing experience and course attendance suffice to qualify him	Court: No abuse of discretion qualifying him narrowly for identification only
Whether Hunnicutt could testify beyond identification about testing/analysis	Testimony about testing/weight exceeded his qualification and should be excluded	Such testimony was admissible and reliable for proving weight element	Court: Admission of analysis/weight testimony exceeded the limited qualification and was an abuse of discretion
Whether the State laid foundation for accuracy of the scale and weight measurement	Foundation insufficient: witness lacked personal knowledge of calibration and did not weigh actual evidence bags	State relied on evidence technician and actual weighing performed at sheriff's office	Court: Foundation inadequate; speculation about calibration and reliance on another agency's scale was insufficient
Whether weighing one empty bag as proxy for six seized bags was a reliable method where charged weight barely exceeded threshold	That method was unreliable and prejudicial because total was only slightly over 10 lb threshold	The bags were similar in appearance and the approach was reasonable	Court: Method unreliable given proximity to statutory threshold; prejudicial and insufficient foundation

State v. Torres, 390 S.C. 618 (2010) (abuse-of-discretion review for admissibility rulings)
State v. Price, 368 S.C. 494 (2006) (standard for reviewing trial court admission of expert testimony)
State v. Douglas, 369 S.C. 424 (2006) (defining abuse of discretion as lacking evidentiary support or controlled by error of law)
State v. Cain, 224 N.J. 410 (2016) (expert testimony common in drug cases to explain packaging and weight)
State v. Manewa, 167 P.3d 336 (2007) (insufficient foundation where expert lacked calibration knowledge and had never calibrated the balance)
State v. Richardson, 285 Neb. 847 (2013) (requiring precise foundation regarding scale accuracy and calibration)