What Does the Prosecutor Need to Prove a DUI? – Guest Post

The government maintains the responsibility to prove driving under the influence charges beyond a reasonable doubt. No self-incrimination requirement exists. Prosecutors must present evidence establishing each DUI offense element. Typically, the arresting officer who conducted the initial stop, observation, and testing request will provide testimony. Officer testimony includes administered tests, results, and any test refusal documentation.

When test results inadequately support allegations, officers may introduce alternative intoxication evidence; however, judicial acquittal becomes more probable without appropriate test results or refusal documentation. The following elements constitute the prosecution’s required proof in DUI cases.

Establishing the Defendant Was Driving

Frequently, arresting officers directly observe defendants operating vehicles. However, in certain situations, officers don’t witness vehicle operation, prosecutors must establish driving through alternative evidence. This commonly occurs in DUI collisions where officers arrive after the incident occurs. Prosecution may utilise witness testimony to establish the defendant’s vehicle operation or admission of driving.

Some cases lack witnesses or admissions. In these situations, prosecution may attempt to demonstrate driving using circumstantial evidence. This potentially includes the alleged driver’s position within the vehicle, the absence of alternative potential drivers, or additional factors suggesting the defendant operated the vehicle.

Observation or Questioning

DUI evidence originates from multiple sources. Typically, law enforcement observes behaviour suggesting traffic law violations. Officers require reasonable suspicion to initiate traffic stops when suspecting impaired driving. Alternatively, they might observe certain behaviours during stops for other traffic violations. Officers subsequently testify regarding observations during these encounters.

Prosecutors potentially introduce statements made during police questioning. Ideally, defendants decline police questioning and request a DUI lawyer. However, officers often obtain responses they subsequently attempt to introduce as evidence during proceedings.

Proving the Defendant was Intoxicated

Prosecution must establish the defendant’s impairment or blood alcohol concentration at or above 0.08% during vehicle operation. This requires the utilisation of breath or blood test results. Defendants require observation before testing to prevent actions that could potentially cause elevated test results.

Prosecution potentially needs expert testimony regarding retrograde extrapolation explaining how post-driving test results accurately reflect driving-time blood alcohol levels. Defence may present expert witnesses, potentially demonstrating below-threshold blood alcohol concentration during driving despite higher subsequent results reflecting increasing levels. Following test refusal, prosecution must demonstrate impairment using alternative evidence, potentially including:

• Driving behaviour evidence
• Field sobriety test performance

Proving the “Driving” Element

Despite terminology suggesting “driving under influence,” most jurisdictions permit conviction without actual driving evidence: Prosecution can establish the “driving” element by demonstrating “operation” or “actual physical control” of vehicles. In these states, driving evidence suffices, but isn’t required for a DUI conviction.

State regulations vary regarding operation or physical control definitions. However, these laws share a common purpose: An intoxicated individual capable of quickly controlling and driving vehicles presents equivalent danger to actively impaired drivers. When determining operation or physical control, Judicial authorities typically consider multiple factors, potentially including:

• Defendant’s conscious state when discovered
• Engine operational status
• Key location
• Defendant’s proximity to vehicle controls

Generally, a closer proximity to potential vehicle operation increases the likelihood of establishing actual physical control.

Endnote

Following a driving under the influence arrest, consult experienced DUI legal counsel. Each jurisdiction maintains distinct regulations, and individual cases involve specific circumstances. Qualified DUI representation can explain applicable laws in your situation and assist with determining the optimal strategic approach.