Background
On July 6, 2022, a traffic crash on Interstate 69 in Delaware County killed semi-truck driver Leslie Garrett. Nicholas Wemes, driving a Dodge Ram 3500 that struck the rear of Garrett’s trailer, admitted he was following too closely and didn’t brake quickly enough. While officers noted Wemes was distraught and shaken, none observed signs of intoxication. However, because the crash involved serious injuries, Wemes consented to a blood draw. Toxicology testing returned positive for Delta-9 Carboxy THC (THC-COOH) at 30 ng/mL and Delta-9 THC at 2.1 ng/mL.
In January 2024, the State charged Wemes with Level 4 felony causing death when operating a vehicle with a schedule I or II controlled substance in the blood under Indiana Code section 9-30-5-5(a)(2) and Level 5 felony reckless homicide. Wemes filed combined motions to suppress, exclude evidence, and dismiss the charges, arguing that Indiana’s legalization of hemp—which may contain up to 0.3 percent Delta-9 THC by dry weight—meant the State must prove the THC in his blood derived from illegal marijuana rather than legal hemp. He also argued the federal Farm Bill preempted Indiana’s per se criminalization of driving with any THC in one’s blood. The trial court denied all motions, and Wemes brought this interlocutory appeal.
The Court’s Holding
The Court of Appeals affirmed. On the statutory interpretation issue, the court held that Indiana Code section 9-30-5-5(a)(2) criminalizes causing death while operating a vehicle with a schedule I or II controlled substance in the blood—without regard to whether the substance derived from legal hemp or illegal marijuana. The court emphasized that the statute does not distinguish culpability based on the legal or illegal source of the substance, drawing an analogy to alcohol: “Like alcohol, causing death when driving with THC in one’s blood is criminalized whether the source of the THC was legal or illegal to possess or consume.” Delta-9 THC remains a schedule I controlled substance under Indiana law regardless of its source.
The court also declined to extend the holdings of Lakes v. State (2024) and Fedij v. State (2022), which required the State to prove THC concentration above 0.3 percent to sustain marijuana possession charges. Those holdings were specific to possession offenses and did not address the distinct conduct proscribed by the vehicular homicide statute—driving with any THC in one’s blood and causing death.
On federal preemption, the court found Wemes waived the argument because he failed to identify which type of preemption (express, conflict, or field) applied and provided no cogent reasoning supported by relevant authority. His reply brief offered no clarification beyond asserting the State must prove the THC came from marijuana rather than hemp.
Key Takeaways
- Indiana Code section 9-30-5-5(a)(2) is a per se statute: any amount of Delta-9 THC in a driver’s blood triggers criminal liability if the driver causes death or serious injury, regardless of whether the THC came from legal hemp or illegal marijuana. The State need not prove impairment or the source of the THC.
- The Lakes and Fedij line of cases—which require proof of THC concentration above the hemp threshold for marijuana possession charges—does not apply to vehicular homicide or OWI charges. These are distinct offenses with different elements.
- Federal preemption challenges to Indiana’s THC-in-blood driving statutes must be properly briefed with identification of the specific preemption framework (express, conflict, or field) and supporting authority. Conclusory assertions of preemption will be deemed waived.
Why It Matters
As hemp-derived THC products become increasingly common in Indiana, this decision draws a clear line: the legality of the THC source is irrelevant when a driver has any detectable THC and causes a fatal or injurious crash. Indiana practitioners should advise clients that using legal hemp products containing Delta-9 THC can still expose them to Level 4 felony liability if they drive and someone is killed or seriously injured. The statute provides a defense only for THC present “in accordance with a valid prescription” under section 9-30-5-5(d)—not for legal hemp consumption.
For criminal defense attorneys, the opinion forecloses the hemp-source defense in vehicular homicide cases but leaves open the possibility that a properly briefed federal preemption argument could gain traction in a future case. The court’s treatment of the preemption issue as waived suggests the door is not fully closed. Additionally, the destruction of Wemes’s blood sample before retesting was possible adds a practical dimension: defense attorneys in similar cases should move quickly to preserve samples if they intend to challenge the source or concentration of detected THC.