Understanding the Impact of Probable Cause in DWI Cases

Wilmoth v. Department of Revenue, No. SC99655

In an important ruling that clarifies the use of preliminary breath test (PBT) results in DWI cases, the Missouri Supreme Court’s decision in Wilmoth v. Director of Revenue offers critical insights for those charged with DWI. This case underscores the complexity of  probable cause in traffic stops involving suspected alcohol use, setting a precedent for how PBT results can be utilized in court.

The Missouri Supreme Court issued an opinion on June 13, 2023, affirming the circuit court’s judgment in the case of David Wilmoth v. Director of Revenue. David Wilmoth appealed the suspension of his driver’s license under section 302.505, following a court finding of probable cause for an alcohol-related traffic offense and driving with a blood alcohol content (BAC) of 0.08% or more.

Wilmoth argued that the circuit court erred in admitting testimony about a preliminary breath test (PBT) result prior to his arrest, which indicated a BAC greater than 0.08%, claiming it violated section 577.021.3. He also contended that the finding of probable cause for an alcohol-related offense was not supported by substantial evidence and was against the weight of the evidence.

The Supreme Court found that the result of the PBT is admissible as evidence of probable cause to arrest under section 577.021.3. The court held that the circuit court did not err in allowing testimony about the PBT result being greater than 0.08%, as this was one of the facts known to the arresting officer at the time of arrest.

The case’s background involves a domestic assault report at Wilmoth’s residence in November 2019. Deputy Mazer, responding to the report, observed Wilmoth driving a utility terrain vehicle without signaling for a turn. During the traffic stop, Mazer detected alcohol on Wilmoth’s breath, observed bloodshot and watery eyes, and noted Wilmoth’s admission of drinking earlier. Wilmoth underwent a PBT showing a BAC of 0.11% and refused other field sobriety tests. Later breath tests at the county jail showed BAC levels of 0.082% and 0.086%.

Wilmoth’s license suspension was sustained by an administrative hearing officer, and the circuit court affirmed this decision, leading to the appeal.

The Supreme Court upheld the circuit court’s judgment, finding substantial evidence supporting the probable cause for arrest and concluding that the circuit court’s judgment was not against the weight of the evidence. Therefore, the suspension of Wilmoth’s license was affirmed.