Intervening Cause in Florida DUI Cases

In certain DUI cases involving property damage, injury, or death, the issue of causation becomes central. Prosecutors must prove not only that the defendant was driving under the influence of alcohol or drugs, but also that their impairment directly caused the resulting harm.

An independent intervening cause, an unexpected event or action that interrupts the chain of causation, can sometimes provide a complete defense or lead to a reduction in charges.

Although rarely used, this defense can be powerful in cases where the injuries or damages were not the natural or probable result of the defendant’s conduct.

Information Center

• When the Intervening Cause Defense Applies
• Common Scenarios Involving Intervening Causes
• Legal Standards for Proving Causation in Florida
• Importance of Jury Instructions on Intervening Cause
• Relationship to DUI Manslaughter and Serious Bodily Injury Charges
• Defenses Related to Causation
• Special Enhancements for BUI

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When the Intervening Cause Defense Applies

Florida law recognizes that causation requires more than just being part of a sequence of events leading to harm. The prosecutor must provide causation for certain types of DUI cases, including the following:

1. DUI with property damage;
2. DUI with non-serious bodily injury;
3. Felony DUI with serious bodily injury; and
4. Felony DUI Manslaughter.

In these cases, the person accused of the crime may attempt to show at trial that some intervening cause resulted in bodily injury or property damage. An intervening cause is an event or action that changes the natural progression of events that would have otherwise occurred.

If an independent event breaks that causal chain, then the defendant may argue that the resulting injury or death cannot be legally attributed to them.

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Common Scenarios Involving Intervening Causes

Some common examples include:

• Medical negligence after a crash: A victim survives an initial collision but dies later due to medical malpractice. The defense can argue that the death resulted from subsequent medical error, not from the defendant’s driving.
• Another driver’s reckless or unlawful actions: If a second motorist’s conduct, such as running a red light, was the sole proximate cause of the accident, the DUI defendant may not be held responsible for the resulting injury or damage.
• Mechanical failure or environmental hazards: Unexpected brake failure, tire blowouts, or debris in the roadway can create intervening events that disrupt the causal link between the accused’s impairment and the harm.

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Legal Standards for Proving Causation in Florida

In cases where injury or death results, prosecutors must prove beyond a reasonable doubt that:

1. The defendant was driving or in actual physical control of a vehicle while impaired by alcohol or drugs; and
2. The defendant’s operation of the vehicle was the proximate cause of the property damage, bodily injury, or death.

Florida courts define “proximate cause” as the natural, direct, and continuous sequence of events unbroken by any efficient, independent cause.

If the defense can show that another event was the sole proximate cause, then the element of causation fails, and the defendant cannot be convicted of the enhanced DUI offense.

However, Florida appellate courts generally hold that if the defendant’s conduct contributed at all to the result, and the intervening event was foreseeable, the chain of causation remains intact.

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Importance of Jury Instructions on Intervening Cause

Florida trial courts have discretion to give an independent intervening cause instruction only when the evidence supports it. The defense must demonstrate:

• Evidence of an external, independent event;
• Proof that this event was not reasonably foreseeable; and
• That the intervening cause, not the defendant’s impairment, directly caused the injury or loss.

If the intervening cause is shown to be the sole proximate cause, the jury may be instructed that the defendant is not criminally liable for the resulting harm.

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Relationship to DUI Manslaughter and Serious Bodily Injury Charges

The intervening cause defense most often arises in DUI manslaughter or DUI with serious bodily injury prosecutions under Florida Statute § 316.193(3).

Because these crimes require proof of causation, any evidence showing that a victim’s death or injury resulted from subsequent events, or the impairment merely placed the defendant at the scene can weaken the prosecution’s case.

For instance, if the State cannot prove that the intoxicated driver’s operation directly caused the death, and the fatality instead stemmed from a medical or third-party event, the DUI manslaughter charge may be reduced or dismissed.

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Defenses Related to Causation

An experienced DUI defense attorney can raise multiple causation-based defenses, including:

• Intervening cause (independent act breaks the chain of events)
• Lack of proximate cause (State fails to prove causation beyond reasonable doubt)
• Mechanical failure or environmental interference
• Superseding act of negligence or intentional misconduct by another person

These defenses can reduce a felony DUI with injury or death to a misdemeanor DUI, or even result in case dismissal if causation cannot be established.

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Attorney for DUI Manslaughter and Intervening Cause Defense in Tampa, FL

If you were charged with DUI with serious bodily injury or DUI manslaughter, and you believe the alleged harm resulted from another cause, contact an experienced DUI defense attorney immediately.

At the Sammis Law Firm, our attorneys understand the complex medical, mechanical, and factual issues involved in proving or disputing causation in DUI prosecutions.

We work with accident reconstruction experts, medical professionals, and forensic toxicologists to show when an injury or fatality was caused by independent factors, not intoxicated driving.

Contact Our Tampa DUI Defense Lawyers

Call (813) 250-0500 today to schedule a free and confidential consultation with an experienced attorney at the Sammis Law Firm.

We represent clients throughout Hillsborough, Pinellas, Pasco, Polk, and Hernando Counties, including Tampa, Brandon, Clearwater, St. Petersburg, and New Port Richey, FL.

Protect your rights and fight for the strongest possible defense when causation in your DUI case is in dispute.