Stevens v. State: Expert Testimony as a Sufficient Foundation for LC-MS/MS Blood-Toxicology Evidence

Introduction

In Stevens v. State, the Supreme Court of Delaware addressed whether the State must produce written calibration records for laboratory equipment—specifically liquid-chromatography tandem mass-spectrometry (LC-MS/MS) machines—before blood-toxicology results may be admitted in a driving-under-the-influence-of-drugs (DUID) prosecution. Kevin Stevens, convicted of DUID and driving with a suspended license, argued on appeal that without documentary proof of calibration, the Superior Court abused its discretion in admitting two blood-test results that showed flubromazepam and fentanyl in his bloodstream.

The Court rejected Stevens’s argument, holding that live testimony from qualified forensic chemists—including the Chief Forensic Toxicologist—was a sufficient foundation. The decision clarifies that Delaware does not impose a bright-line rule requiring calibration documents where expert witnesses with first-hand laboratory knowledge testify to the instruments’ accuracy. It distinguishes the earlier McConnell v. State line of breath-test cases, carving out an important evidentiary distinction between field intoxilyzer devices and laboratory-based analytical equipment.

Summary of the Judgment

• The Superior Court’s evidentiary ruling admitting LC-MS/MS results was reviewed for abuse of discretion; no abuse was found.
• The Supreme Court declined to adopt a bright-line rule requiring calibration documents whenever blood-toxicology evidence is offered.
• Expert testimony from analytical chemists and the Chief Forensic Toxicologist—who possessed and reviewed the calibration data—met the foundational requirements of Delaware Rules of Evidence (D.R.E.) 702, 703, and 705.
• McConnell was distinguished: it governs police-operated intoxilyzers, not laboratory-run LC-MS/MS instruments.
• Because Stevens neither requested the bench notes in discovery nor demonstrated any actual inaccuracy, the presumption of regularity applied.
• All convictions and the sentence (two years, suspended after six months) were affirmed.

Analysis

Precedents Cited and Distinguished

McConnell v. State (1994) established that a certification sheet from the State Chemist is necessary to lay a foundation for intoxilyzer breath results. The Court in Stevens emphasized:

• Intoxilyzers are administered by police officers, who are not scientific experts.
• Certification sheets function as a surrogate for live expert testimony.
• McConnell also announced a presumption that the State Chemist acts “carefully and in a prudent manner” absent contrary evidence.

The Court then drew a functional distinction between police-operated field devices and laboratory-operated analytical instruments, noting that LC-MS/MS tests are performed by experts themselves. Consequently, a separate documentary requirement would be superfluous when those experts testify.

Other precedents examined include:

• Tolson v. State, 900 A.2d 639 (Del. 2006) – reiterates that expert testimony is needed to establish reliability of scientific instruments.
• Perry v. Berkley, 996 A.2d 1262 (Del. 2010) – mandates judicial gatekeeping under D.R.E. 702.
• Cedeno v. State, 2023 WL 6323598 (Del. Super.) – summarizing intoxilyzer calibration practice and reinforcing McConnell.
• Federal case United States v. Sheppard (W.D. Ky. 2021) was raised belatedly by the defense; the Court held it waived and fact-distinguishable because calibration data there was entirely missing, not merely undisclosed.

Legal Reasoning

1. Standard of Review: Evidentiary rulings overturned only for “abuse of discretion.”
2. D.R.E. 702–705 Framework:
   • The experts’ qualifications were uncontested.
   • D.R.E. 703 allows experts to base opinions on facts/data “reasonably relied upon” by experts in the field—even if those data are not themselves admitted.
   • D.R.E. 705(b) gives the opponent the right to voir dire the expert on underlying data, which Stevens did not invoke.
3. Discovery Obligations:
   • Superior Court Crim. R. 16(b)(1)(F) would entitle Stevens to calibration data upon request; he made no specific request and no pre-trial discovery dispute arose.
   • Two State witnesses physically possessed the calibration bench notes at trial; defense counsel declined to inspect them.
4. Presumption of Regularity: Because Stevens presented no affirmative evidence of malfunction or mis-calibration, the Court applied the presumption that State chemists acted properly, echoing McConnell.
5. Policy Considerations: Requiring calibration documents in every blood-test case would impose form-over-substance where qualified scientists can testify directly. The Court refused to conflate evidentiary safeguards needed for field devices with those appropriate for laboratory instruments.

Potential Impact

• DUID Prosecutions: Prosecutors can rely on expert testimony without fear that absent calibration paperwork automatically renders LC-MS/MS results inadmissible.
• Defense Strategy: Defense counsel must proactively request calibration data in discovery and consider expert cross-examination or independent testing rather than simply objecting on foundational grounds.
• Court Efficiency: Trials may proceed with fewer foundational disputes, reducing the need to summon custodians of records solely to introduce bench notes.
• Legislative Context: The ruling aligns with 21 Del. C. §4177(h)(1), which treats a toxicologist’s signed report as prima facie evidence, reinforcing statutory streamlining of DUI evidence.
• National Trend: Although some jurisdictions (e.g., the federal district court in Sheppard) have required production of calibration documents, Stevens signals Delaware’s more flexible, expert-centric approach.

Complex Concepts Simplified

• LC-MS/MS (Liquid Chromatography–Tandem Mass Spectrometry): a two-step analytical method. Liquid chromatography separates components of the blood; mass spectrometry identifies and quantifies them with high precision.
• ELISA (Enzyme-Linked Immunosorbent Assay): a screening test that detects drug classes but requires confirmation (here via LC-MS/MS).
• Calibration: Routine testing of an instrument with known standards to ensure it produces accurate readings. In the lab, chemists keep “bench notes” recording calibration runs.
• D.R.E. 702/703/705: Delaware Rules of Evidence governing expert qualifications (702), basis of opinion (703), and disclosure of underlying facts (705).
• Presumption of Regularity: A legal presumption that public officials (e.g., state chemists) perform their duties properly unless shown otherwise.
• Intoxilyzer vs. LC-MS/MS: Intoxilyzer is a field breath-testing device operated by police; LC-MS/MS is a lab technique run by scientists. Foundational requirements differ because operator expertise differs.

Conclusion

Stevens v. State cements an important evidentiary principle in Delaware: live expert testimony from qualified forensic scientists can, by itself, lay a proper foundation for the admission of blood-toxicology results obtained through sophisticated laboratory instruments. The Court’s refusal to impose a documentary calibration prerequisite recognizes the practical realities of modern forensic testing and preserves judicial economy without sacrificing reliability safeguards. Defense counsel retain robust tools—discovery, voir dire, independent experts—to probe and contest laboratory analyses, but a default insistence on calibration paperwork is no longer viable. The decision thus recalibrates (pun intended) the evidentiary landscape for DUID prosecutions and offers clear guidance on the interplay between scientific expertise and foundational proof in Delaware courts.