When someone is arrested for DUI, the blood alcohol concentration (BAC) measured at the police station or hospital is not necessarily the same as their BAC when they were actually driving.

Alcohol takes time to absorb into the bloodstream. Depending on when the person had their last drink, what they ate, and their individual physiology, their BAC at the time of driving could have been significantly lower—or even below the legal limit.

This is not a technicality. It is science. And in this DUI manslaughter case, a forensic toxicologist used that science to prove our client was not unlawfully impaired at the time of the crash.  I am Tampa Criminal Defense Attorney Rocky Brancato. This post is part of our forensic series put out by the Brancato Law Firm, P.A., your Tampa criminal forensic evidence law firm.

The Case: A Tragic Crash and a Grieving Mother

Our client was involved in a fatal crash at an intersection. She was making a left-hand turn when another vehicle T-boned her car. Tragically, her own child died in the collision.

When her BAC was measured after the crash, it was above the legal limit of 0.08. Based on that number, she was charged with DUI manslaughter—a first-degree felony under Florida Statute 316.193, punishable by up to 15 years in prison.

But the BAC number alone did not tell the whole story. And the crash itself raised serious questions about who was really at fault.

The Video: Evidence of the Other Driver’s Speed

Video footage of the crash revealed something critical: the other driver was traveling at nearly twice the posted speed limit when he entered the intersection.

Our client was making a left turn—a maneuver that requires judging the distance and speed of oncoming traffic. But how can anyone accurately judge an oncoming vehicle that is traveling far faster than any reasonable driver would expect?

This raised the first major defense issue: causation. Even if our client had alcohol in her system, was her driving actually the cause of the crash? Or was the crash caused by the other driver’s reckless speed?

Expert #1: The Accident Reconstructionist

To address the causation question, we retained an accident reconstructionist—a former Captain with the Florida Highway Patrol who had investigated hundreds of fatal crashes during his career.

He analyzed the video footage, the physical evidence, and the dynamics of the collision. His conclusion: based on the speed the other driver was traveling, our client would not have been able to anticipate that her left-hand turn would result in a collision.

In his expert opinion, her decision to turn was not at fault. The other driver’s excessive speed was the cause of the crash.

However, the accident reconstructionist could not render an opinion on our client’s BAC. That was a different question requiring a different expert.

Expert #2: The Forensic Toxicologist

The prosecution’s case rested heavily on the BAC measurement taken after the crash. They assumed that if our client’s BAC was above 0.08 at the station, it must have been above 0.08 when she was driving.

But that assumption ignores the science of alcohol absorption.

We retained a forensic toxicologist to analyze our client’s statements to police. Those statements revealed important details:

• She had eaten a big meal before leaving
• She had consumed a drink right before she left
• The crash occurred shortly after she began driving

The Forensic Toxicologist’s Analysis

Using retrograde extrapolation, the forensic toxicologist worked backward from the BAC measurement taken after the crash. She factored in:

• The time between the crash and the BAC test
• The time of our client’s last drink
• The large meal she had consumed (which slows absorption)
• Standard rates of alcohol absorption and elimination

Her conclusion was significant: based on the timing of the last drink and the meal, that final drink would not have been fully absorbed at the time our client was driving.

In other words, our client was not unlawfully under the influence at the time of the crash. Her BAC rose to above 0.08 only later—after the crash, during the absorption phase—when the alcohol from that last drink finally entered her bloodstream.

What This Case Teaches About DUI Defense

• The BAC at the station is not necessarily the BAC at the time of driving. Retrograde extrapolation can establish that the defendant’s BAC was lower—or below the legal limit—when they were actually behind the wheel.
• A recent drink may not have been absorbed yet. Alcohol consumed shortly before driving may not enter the bloodstream until after the crash, causing the BAC to rise between the incident and the test.
• Food slows alcohol absorption. A large meal can significantly delay how quickly alcohol enters the bloodstream, which affects the timing analysis.
• Multiple experts may be needed for different issues. In this case, causation and impairment were separate questions requiring separate experts.
• The defendant’s own statements can help the defense. Statements about when she drank and what she ate provided the data the toxicologist needed for the retrograde extrapolation.

Frequently Asked Questions

What is retrograde extrapolation?

Retrograde extrapolation is a forensic toxicology technique used to estimate a person’s blood alcohol concentration at an earlier time based on a later measurement. By analyzing factors like when the person drank, what they ate, and standard absorption rates, a toxicologist can calculate whether BAC was higher or lower at the time of driving.

Can my BAC go up after I stop drinking?

Yes. Alcohol takes time to absorb into the bloodstream—typically 30 minutes to 2 hours. If you had a drink shortly before driving, your BAC may continue to rise after you stop drinking, during the absorption phase. This means your BAC at the police station could be higher than your BAC when you were driving.

What is a forensic toxicologist?

A forensic toxicologist is a scientist who specializes in the effects of drugs and alcohol on the human body and how to detect them. In criminal cases, they analyze blood, urine, and other samples, and can testify about impairment, absorption rates, and retrograde extrapolation.

Does eating affect alcohol absorption?

Yes. Food in the stomach—especially a large meal—significantly slows alcohol absorption. This means that if you eat before drinking, the alcohol will take longer to enter your bloodstream. A forensic toxicologist considers this factor when calculating BAC at the time of driving.

What is DUI manslaughter in Florida?

Under Florida Statute 316.193, DUI manslaughter occurs when a person driving under the influence causes the death of another person. It is a second-degree felony punishable by up to 15 years in prison. If the driver knew or should have known the crash occurred and failed to render aid, it becomes a first-degree felony punishable by up to 30 years.

Do I need both an accident reconstructionist and a toxicologist?

It depends on the case. If causation is disputed—meaning it is unclear whether your driving caused the crash—an accident reconstructionist can address that issue. If impairment is disputed, a forensic toxicologist can address BAC at the time of driving. Some cases require both experts to cover different aspects of the defense.

Facing DUI or DUI Manslaughter Charges?

A BAC number is not the end of the story. The prosecution must prove you were impaired at the time of driving—not at the time of the test. With the right forensic analysis, that assumption can be challenged.

For over 25 years, I have defended clients against serious charges in Tampa Bay. I understand the science of alcohol absorption, I work with forensic toxicologists and accident reconstructionists, and I know how to present complex technical evidence to juries in a way they can understand.

Call (813) 727-7159 for a Confidential Consultation

The Brancato Law Firm, P.A.

620 E. Twiggs Street, Suite 205, Tampa, FL 33602

Serving Hillsborough, Pinellas, and Pasco Counties

Part of the Forensic Evidence Series

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What Is Trenton’s Law?

On October 1, 2025, a sweeping new Florida law known as Trenton’s Law took effect, fundamentally changing how DUI and BUI offenses are prosecuted and punished in Florida. This legislation represents one of the most significant expansions of DUI penalties in recent Florida history.

Specifically, Trenton’s Law accomplishes four major objectives: it criminalizes refusal to submit to chemical testing, enhances penalties for repeat offenders, increases sentencing for DUI and BUI manslaughter, and updates Florida’s Criminal Punishment Code to impose higher sentencing points for impaired driving offenses. Consequently, anyone arrested for DUI or BUI after October 1, 2025 faces substantially more severe consequences than under prior law.

Breath Test Refusal Is Now a Crime

One of the most significant changes under Trenton’s Law is the criminalization of breath and urine test refusal. Prior to October 1, 2025, refusing a lawful request for chemical testing resulted in an administrative license suspension but was not itself a criminal offense.

Under the new law, refusing to submit to testing now carries the following criminal penalties:

Moreover, officers must now clearly advise drivers that refusing a lawful test is not only grounds for license suspension but also a crime that can be prosecuted. This expanded implied consent warning ensures defendants cannot claim ignorance of the criminal consequences.

Enhanced DUI and BUI Manslaughter Penalties

Trenton’s Law dramatically increases penalties for DUI manslaughter, BUI manslaughter, vehicular homicide, and vessel homicide—particularly for defendants with prior convictions. Under the new law, these offenses are now elevated to first-degree felonies when the defendant has a prior conviction for any of these offenses.

Prior Convictions That Trigger Enhancement

A defendant’s current charge will be elevated to a first-degree felony if they have any prior conviction for:

• DUI manslaughter (Florida Statute § 316.193(3)(c)3)
• BUI manslaughter (Florida Statute § 327.35(3)(c)3)
• Vehicular homicide (Florida Statute § 782.071)
• Vessel homicide (Florida Statute § 782.072)

Trenton’s Law: Before and After Comparison

Offense Severity Ranking Changes

Trenton’s Law also updates Florida’s Offense Severity Ranking Chart under the Criminal Punishment Code. DUI, BUI, vehicular homicide, and vessel homicide offenses have been moved higher on the chart, resulting in significantly more sentencing points.

In Florida’s sentencing system, higher offense severity rankings translate directly into longer mandatory minimum sentences and increased prison exposure. Therefore, even defendants without prior convictions will face harsher guideline sentences for DUI and BUI offenses committed after October 1, 2025.

Boating Under the Influence (BUI) Enhancements

Trenton’s Law applies identical enhancements to boating under the influence offenses. For Tampa Bay area boaters—including those in Hillsborough, Pinellas, and Pasco counties—this means that BUI arrests now carry the same serious consequences as DUI arrests.

Specifically, the law provides that:

• Refusing breath or urine testing during a BUI investigation is now a criminal offense
• BUI manslaughter with a prior conviction for DUI manslaughter, BUI manslaughter, vehicular homicide, or vessel homicide is a first-degree felony
• Vessel homicide carries enhanced sentencing points under the Criminal Punishment Code

What Trenton’s Law Means for Tampa Bay Drivers and Boaters

For drivers and boaters across Tampa Bay—including Hillsborough, Pinellas, and Pasco counties—Trenton’s Law significantly raises the stakes in DUI and BUI cases. The changes affect everyone from first-time offenders to those with prior records.

A refusal to blow is no longer just an administrative suspension—it can now lead to a permanent criminal record. Likewise, repeat DUI or BUI offenders face life-altering felony enhancements that can result in decades of prison time.

If you or a loved one is charged under this new law, it is crucial to work with an experienced defense attorney who understands both the criminal trial process and the nuances of Florida’s sentencing guidelines.

Frequently Asked Questions: Trenton’s Law

What is Trenton’s Law in Florida?

Trenton’s Law is a 2025 Florida statute that significantly increases penalties for DUI and BUI offenses. The law criminalizes breath test refusal, enhances penalties for repeat offenders, elevates DUI and BUI manslaughter to first-degree felonies for defendants with prior convictions, and increases sentencing points under Florida’s Criminal Punishment Code. It takes effect October 1, 2025.

Does refusing a breath test now carry criminal charges in Florida?

Yes. Under Trenton’s Law, refusing to submit to a lawful breath or urine test is now a criminal offense. A first refusal is a second-degree misdemeanor punishable by up to 60 days in jail and a $500 fine. A second or subsequent refusal is a first-degree misdemeanor punishable by up to one year in jail and a $1,000 fine.

What happens if someone with a prior DUI manslaughter conviction causes another fatal crash?

Under Trenton’s Law, they can now be charged with a first-degree felony, which carries a maximum penalty of 30 years in state prison. This is a dramatic increase from the previous second-degree felony classification, which carried a maximum of 15 years.

Does Trenton’s Law apply to boating under the influence (BUI)?

Yes. The law applies identical enhancements to BUI offenses. Refusing testing during a BUI investigation is now a criminal offense, and BUI manslaughter with a prior conviction is now a first-degree felony. Vessel homicide also receives enhanced sentencing points.

When does Trenton’s Law take effect?

Trenton’s Law takes effect on October 1, 2025. All DUI and BUI arrests occurring on or after this date will be subject to the new enhanced penalties, including criminal charges for refusal.

Should I refuse the breath test under the new law?

This is a complex legal question that depends on your specific circumstances. Under Trenton’s Law, refusal now carries criminal penalties in addition to license suspension—but providing a breath sample can also provide evidence for the prosecution. An experienced DUI attorney can help you understand the strategic considerations based on your individual situation.

What prior convictions trigger the first-degree felony enhancement?

The first-degree felony enhancement applies if the defendant has any prior conviction for DUI manslaughter, BUI manslaughter, vehicular homicide, or vessel homicide. Any one of these prior convictions will elevate a new DUI manslaughter, BUI manslaughter, vehicular homicide, or vessel homicide charge to a first-degree felony.

How can a Tampa DUI attorney help with charges under Trenton’s Law?

An experienced Tampa DUI attorney can challenge the legality of the traffic stop, question the administration of field sobriety tests, challenge breath test results, file motions to suppress evidence, negotiate with prosecutors for reduced charges, and advocate for alternative sentencing. Given the enhanced penalties under Trenton’s Law, aggressive defense from the earliest stages is critical.

Related:

• Tampa DUI Lawyer – Full DUI defense services
• Tampa CDL DUI Suspension Attorney – Commercial license defense
• Retrograde Extrapolation: Challenging BAC Evidence in Florida DUI Cases
• Tampa Boating Law 2025 Lucy’s Law

Why Breath Test Machine Maintenance Matters

When police arrest someone for DUI in Florida, prosecutors typically rely on the Intoxilyzer 8000 to prove impairment. Indeed, this breath testing machine serves as the gold standard for measuring blood alcohol content. However, its results depend entirely on the maintenance and calibration procedures that keep it accurate.

If technicians fail to properly maintain the Intoxilyzer, courts can exclude its results from evidence. As a result, this exclusion can mean the difference between a conviction and a dismissal.

The Case: State v. Kilburn, Marano, and Depauw

In this consolidated appeal, three DUI defendants challenged their breath test results on identical grounds: specifically, the Intoxilyzer 8000 used to test them had undergone an unauthorized repair.

The critical fact proved simple: FDLE inspectors replaced the breath tube on the Intoxilyzer 8000. However, under Florida’s rules, only the manufacturer or an approved repair facility may perform such repairs. Because the repair violated Florida’s administrative rules, the court concluded that technicians had not properly maintained the machine. Therefore, the presumption of accuracy that normally applies to breath test results disappeared.

Common Grounds to Challenge Intoxilyzer Results

The Kilburn case focused on unauthorized repairs. However, defense attorneys can challenge Intoxilyzer 8000 results on many other grounds in Florida DUI cases:

How an Experienced DUI Attorney Investigates Breath Test Evidence

At The Brancato Law Firm, P.A., we examine every detail of DUI cases. Specifically, we investigate the complete maintenance and inspection history of the Intoxilyzer 8000 used to test you. Furthermore, this investigation includes:

• First, requesting all maintenance logs and repair records for the specific machine
• Second, reviewing FDLE inspection reports for compliance with Florida Administrative Code
• Third, verifying the breath test operator held valid certification at the time of testing
• Additionally, examining video evidence to confirm officers followed the 20-minute observation period
• Moreover, identifying any unauthorized repairs or gaps in the maintenance chain
• Finally, deposing FDLE inspectors and breath test operators when necessary

As a result, this detailed investigation frequently reveals issues that provide grounds to suppress breath test evidence—just as the defense attorneys accomplished in Kilburn.

Frequently Asked Questions: Intoxilyzer Maintenance and DUI Defense

Can courts throw out breath test results if technicians failed to properly maintain the Intoxilyzer?

Yes. As the Kilburn case demonstrates, Florida courts will exclude Intoxilyzer 8000 results if the State cannot prove technicians maintained the machine according to Florida Administrative Code requirements. Specifically, this includes proper inspections, authorized repairs, and calibration procedures.

What qualifies as an “unauthorized repair” on an Intoxilyzer 8000?

Under Florida law, only the manufacturer or an approved repair facility may perform repairs on the Intoxilyzer 8000. In Kilburn, for example, FDLE inspectors replaced the breath tube themselves—a repair they lacked authorization to perform. Because this violated Florida’s rules, the court excluded the breath test results.

How often must FDLE inspect the Intoxilyzer 8000 in Florida?

Florida Administrative Code Rule 11D-8 requires FDLE to inspect the Intoxilyzer 8000 at least once per calendar month. Therefore, if gaps exist in the inspection records—or if officers used the machine during a period when FDLE missed inspections—this can provide grounds to challenge the results.

What is the 20-minute observation period?

Before administering a breath test, officers must observe the subject for at least 20 minutes. During this time, they must ensure the subject does not eat, drink, smoke, vomit, or put anything in their mouth. Essentially, this prevents mouth alcohol contamination from affecting the results. Consequently, failure to properly conduct this observation can provide grounds to challenge the test.

Can I request the maintenance records for the Intoxilyzer used in my case?

Yes. Your defense attorney can subpoena all maintenance logs, repair records, and inspection reports for the specific Intoxilyzer 8000 that officers used to test you. Indeed, these records prove essential for identifying potential grounds to challenge the breath test results.

What happens if the court excludes breath test results in my DUI case?

Without breath test results, prosecutors must rely on other evidence—such as field sobriety tests, officer observations, and video footage. As a result, this often leaves them with a significantly weaker case. Depending on the remaining evidence, the State may reduce charges or dismiss them entirely.

Does the officer’s certification affect breath test validity?

Yes. The breath test operator must hold valid certification at the time of testing. Therefore, if the officer’s certification had expired or the officer obtained it improperly, this can provide grounds to challenge the breath test results.

Should I refuse a breath test in Florida?

Refusing a breath test in Florida carries significant consequences. Specifically, implied consent laws trigger automatic license suspension and a separate charge apart from the DUI. However, every case presents different circumstances. If police have already arrested you for DUI—whether you took the test or refused—contact an experienced DUI defense attorney immediately to discuss your options.

Related:

• Tampa DUI Lawyer – Full-service DUI defense
• Trenton’s Law – Enhanced DUI and BUI Penalties
• Fight Your DUI Charge: Proven Defense Strategies
• How to Challenge Field Sobriety Exercises in Tampa

What Happened in the Karls Case

Ricky Lee Karls, Jr. was convicted of DUI with property damage after crashing his motorcycle in Safety Harbor. The State presented evidence including bodycam footage, field sobriety exercises, and a urine drug screen indicating impairment.

The court barred the defense from telling the full story. Karls’ mother was ready to testify that she had been with her son until approximately 30 minutes before the crash and never saw him drink or use drugs. The trial court excluded her testimony as “irrelevant,” claiming that the half-hour gap was too large to be meaningful.

The Second District disagreed and reversed the jury’s DUI conviction.

The Right to Present a Full Defense – DUI Conviction Reversed

On appeal, the court ruled that excluding the mother’s testimony was a clear abuse of discretion and a violation of Karls’ constitutional rights. Even if a witness can’t account for every moment before an incident, their observations can still raise reasonable doubt. The case was reversed and remanded for a new trial.

This ruling reinforces an essential principle: courts should not dismiss defense evidence that could support innocence simply because it doesn’t fit neatly into the State’s theory.

How The Brancato Law Firm, P.A. Protects Your Rights

Cases like Karls sharply remind us that Florida courts often stack the deck against defendants. Judges and prosecutors may try to limit what the jury hears—but with the right defense team, you can fight back.

At The Brancato Law Firm, P.A., Rocky Brancato personally handles every DUI and criminal case. He draws on over 25 years of experience and a background in elite major crimes litigation. We know what’s admissible, what’s strategic, and how to defend your rights from day one through appeal if necessary.

Need a Tampa DUI Attorney? Don’t wait. Call us today.

The Brancato Law Firm, P.A.
 (813) 727-7159
www.brancatolawfirm.com