A blood alcohol number is a snapshot of one moment, and that moment is almost never the moment the person was driving. Fatal crash cases are often decided by the gap between the two. I learned how much the science matters during my years in the Major Crimes Unit, and I have since tried more than 150 jury trials to verdict. I’m Rocky Brancato, founder of The Brancato Law Firm, P.A., a Tampa criminal defense firm. Our attorneys work with forensic toxicologists and accident reconstructionists in DUI and DUI manslaughter cases because the State’s number rarely tells the whole story.

This post is part of our Forensic Evidence Series. It explains how retrograde extrapolation works, what Florida courts say about it, and how it won an acquittal in a DUI manslaughter case.

How does alcohol absorption change BAC over time?

Blood alcohol rises while alcohol is being absorbed, peaks, and then falls as the body eliminates it. Absorption usually takes from about 30 minutes to 2 hours, depending on what and how much the person drank, whether they ate, and their individual physiology. During that absorption phase, BAC is still climbing. A person tested an hour after a crash can have a higher BAC at the station than they had behind the wheel.

Food is one of the biggest variables. A.W. Jones and K.Å. Jönsson studied this in Food-Induced Lowering of Blood-Ethanol Profiles and Increased Rate of Elimination Immediately After a Meal, Journal of Forensic Sciences (1994). Their work showed that a meal lowers the blood alcohol curve and changes how quickly alcohol is eliminated. Elimination rates also vary from person to person, which A.W. Jones surveyed in Evidence-based survey of the elimination rates of ethanol from blood with applications in forensic casework, Forensic Science International (2010).

Retrograde extrapolation uses those principles to work backward. A toxicologist starts with the measured result and the time it was taken, then accounts for the time of the last drink, food, body weight, and absorption and elimination rates to estimate BAC at the time of driving. The estimate can come out higher, lower, or the same as the measured result. Everything depends on the facts the toxicologist has to work with.

Does the State have to use retrograde extrapolation in a Florida DUI case?

No. Under section 316.193, Florida Statutes, a person commits DUI by driving while impaired or with a blood alcohol level of 0.08 or more, and the State usually proves the level with a test taken after the driving ended. The Florida Supreme Court addressed that gap in Miller v. State, 597 So. 2d 767 (Fla. 1991). The court held that the State’s inability to “relate back” a blood alcohol result to the time of driving “is a question of credibility and weight-of-the-evidence, not of admissibility, provided the test is conducted within a reasonable time after the defendant is stopped.”

A year later, in Haas v. State, 597 So. 2d 770 (Fla. 1992), the court held that retrograde extrapolation is not a condition of conviction. A properly obtained result is prima facie evidence that the level was the same while driving, but the results “are not conclusive,” and the accused may show they do not accurately reflect the level at the time of driving. Justice Kogan’s concurrence in Miller went further: when the State’s only evidence is a toxicologist who says the level may have been under the limit while driving, a judgment of acquittal is required.

That is the opening for the defense. The State can rely on the later number, but it cannot stop the defense from showing the number overstates what the driver’s level was at the wheel. Under section 316.1934, Florida Statutes, a result of 0.08 or more is prima facie evidence of impairment, which a jury may accept or reject.

Can retrograde extrapolation be used against the defendant?

Yes. The science cuts both ways, and Florida appellate courts let both sides use it. In Vitiello v. State, 281 So. 3d 554 (Fla. 5th DCA 2019), a boating under the influence case, the court held the State’s expert extrapolation was admissible under Daubert, and that gaps such as an unknown last drink and unknown food went to weight, not admissibility.

The Second District, which hears appeals from Hillsborough, Pinellas, and Pasco Counties, followed Vitiello in State v. Barber, No. 2D22-2036 (Fla. 2d DCA Apr. 14, 2023). In that DUI manslaughter case, the driver’s blood alcohol was 0.041 eight hours after the crash, and the State’s toxicologist extrapolated it back to 0.161. The trial court excluded the testimony, and the Second District reversed, holding that the missing facts and assumptions go to weight. A defense team has to be ready to cross-examine the State’s extrapolation as hard as it presents its own.

What are the penalties for DUI manslaughter in Florida?

DUI manslaughter is a second-degree felony in Florida, punishable by up to 15 years in prison, and it carries a 4-year mandatory minimum prison sentence. It becomes a first-degree felony in two situations, shown below.

The sentencing ranges come from section 775.082, Florida Statutes. For a broader look at the charge, read What Is DUI Manslaughter in Florida? and How DUI Manslaughter Cases Are Defended in Florida.

These cases are not rare. FLHSMV reported 969 impaired-driving fatalities in Florida in 2023, involving alcohol, drugs, or both, in its Impaired Driving Education Campaign report, and its Traffic Crash Facts Annual Report 2023 counted 363 alcohol-confirmed fatalities that year. Each of those deaths can become a felony prosecution, and many turn on the same two questions our client’s case did.

Case study: how did two experts win a DUI manslaughter acquittal?

Our client was making a left turn at an intersection when another vehicle struck her car broadside. Her own child died in the crash. Her blood alcohol, measured after the crash, was above 0.08, and she was charged with DUI manslaughter. The State’s theory was simple: the number was over the limit, so she was impaired, so she caused the death.

The number did not tell the whole story, and neither did the State’s account of the crash. Our attorneys built the defense around two separate questions, each answered by a different expert.

Question one: who caused the crash? Video of the collision showed the other driver traveling at nearly twice the posted speed limit as he entered the intersection. A left turn requires judging the distance and speed of oncoming traffic, and no driver expects an oncoming car moving at twice the limit. We retained an accident reconstructionist, a former captain with the Florida Highway Patrol who had investigated hundreds of fatal crashes. After analyzing the video, the physical evidence, and the dynamics of the collision, he concluded that, at the speed the other driver was traveling, our client could not have anticipated that her turn would result in a collision. In his opinion, the other driver’s speed caused the crash.

Question two: was she over the limit when she was driving? The reconstructionist could not answer that, so we retained a forensic toxicologist. She worked from our client’s own statements to police: she had eaten a large meal before leaving, she had a drink right before she left, and the crash happened shortly after she began driving. Using retrograde extrapolation, the toxicologist factored in the time between the crash and the test, the time of the last drink, the meal, and standard absorption and elimination rates. Her conclusion was that the last drink would not have been fully absorbed at the time our client was driving. Her blood alcohol rose above 0.08 later, after the crash, as that drink entered her bloodstream.

The result: not guilty. The jury heard both experts, understood the science, and acquitted our client of DUI manslaughter. Each case is unique, and past results do not guarantee future outcomes. More of our results are on our case results page.

What does this case teach about DUI defense?

The case teaches five practical lessons that apply to any DUI or DUI manslaughter charge in Florida:

1. The BAC at the station is not necessarily the BAC behind the wheel. Retrograde extrapolation can show the level was lower, even below 0.08, at the time of driving.
2. A recent drink may not have been absorbed yet. Alcohol consumed shortly before driving can raise BAC after the driving has ended.
3. Food changes the curve. A large meal slows absorption and affects the timing analysis.
4. Causation and impairment are separate questions. In a fatal crash, each may need its own expert.
5. The client’s own statements can help. When and what she drank and ate gave the toxicologist the facts she needed.

Our attorneys also use the State’s evidence the same way. When the prosecution’s toxicologist extrapolates, as in Barber, we test every assumption: the drinking pattern, the absorption state, the elimination rate, and whether the expert ignored food. For more on how experts are used, read Why Expert Witnesses Are Not Optional in Major Crimes Cases and our case study When the Car, Not the Driver, Caused the Crash. You can also visit our Tampa criminal forensic science attorney page.

Frequently asked questions about retrograde extrapolation in Florida

Can my BAC go up after I stop drinking?

Yes. Alcohol keeps entering the bloodstream during the absorption phase, which usually lasts 30 minutes to 2 hours, so BAC can rise after the last drink and after the driving ends. The Brancato Law Firm works with forensic toxicologists who can calculate whether that happened in a client’s case.

Does the State have to prove my BAC at the exact time I was driving?

Not directly. Under Miller v. State, 597 So. 2d 767 (Fla. 1991), and Haas v. State, 597 So. 2d 770 (Fla. 1992), a test taken within a reasonable time is admissible and is prima facie evidence, but it is not conclusive. Our attorneys at The Brancato Law Firm use that opening to present evidence that the level was lower at the wheel.

Can a DUI manslaughter charge be beaten in Florida?

Yes. DUI manslaughter requires proof of impairment or an unlawful alcohol level and proof that the driver’s operation of the vehicle caused or contributed to causing the death, and either element can be contested with forensic evidence. The Brancato Law Firm won a not guilty verdict in a DUI manslaughter case by challenging both, as described above. Learn more on our Tampa homicide defense page.

What is the mandatory minimum sentence for DUI manslaughter in Florida?

A DUI manslaughter conviction carries a 4-year mandatory minimum prison sentence under section 316.193(3), Florida Statutes. Our attorneys at The Brancato Law Firm treat these cases as homicide cases from the first day, because the mandatory minimum leaves little room for error.

Does food really change a DUI blood alcohol result?

Yes. A meal slows how quickly alcohol is absorbed and lowers the peak of the blood alcohol curve, as Jones and Jönsson’s 1994 study in the Journal of Forensic Sciences documented. The Brancato Law Firm gathers receipts, witness accounts, and timelines of what a client ate and drank, because the toxicologist’s opinion is only as good as those facts.

Can the prosecution use retrograde extrapolation against me?

Yes. In State v. Barber, No. 2D22-2036 (Fla. 2d DCA Apr. 14, 2023), the Second District allowed the State’s toxicologist to extrapolate a 0.041 result back to 0.161 in a DUI manslaughter case. Our attorneys at The Brancato Law Firm prepare to cross-examine those assumptions with our own expert.

Facing a DUI or DUI manslaughter charge in Tampa Bay?

Blood samples, crash data, and video can be lost or overwritten quickly, and the defense needs its own experts before the State’s version of events hardens. Our attorneys will secure the evidence, retain the right experts, and build the timeline. The Brancato Law Firm, P.A. was founded by Tampa Criminal Defense Attorney Rocky Brancato. Call (813) 727-7159. You can call us at any hour. Our firm has Spanish-speaking staff, and attorney Jean-Luc Adrien speaks Spanish, Haitian Creole, and French. See our page on Spanish and Haitian Creole criminal defense.

For more about our defense strategies, visit our Tampa Homicide Defense and Tampa DUI Defense pages.

Part of the Forensic Evidence Series. Related case studies: DNA Evidence Defense, Aggravated Child Abuse Defense, Forensic Pathologist, Fingerprint Evidence Is Not as Reliable as You Think, Cell Phone Location Data Can Prove You Were Not There, When Brain Damage Explains Criminal Conduct, When Police Destroy Evidence, When a Confession Is Not a Confession, The Injuries Were Real, But They Were Not From the Alleged Rape, and How a Firearms Expert Kept Out Prejudicial Evidence.

The Brancato Law Firm, P.A.

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

(813) 727-7159

Serving Hillsborough, Pinellas, and Pasco Counties

The Brancato Law Firm, P.A. is a Tampa-based criminal defense practice. We are not affiliated with any other Brancato-named law firms.

Each case is unique, and past results do not guarantee future outcomes. This article is general information, not legal advice.

I’m Rocky Brancato, founder of The Brancato Law Firm, P.A., a Tampa criminal defense firm. I meet the Florida Rule of Criminal Procedure 3.112 qualifications for capital cases, spent years in the Major Crimes Unit of the Hillsborough County Public Defender’s Office, and have taken more than 150 jury trials to verdict. When our attorneys defend a vehicular homicide case, the first call we usually make is to an accident reconstruction expert.

How does Florida define vehicular homicide?

Vehicular homicide is the killing of a human being, or of an unborn child by injury to the mother, “caused by the operation of a motor vehicle by another in a reckless manner likely to cause the death of, or great bodily harm to, another.” That definition comes from section 782.071, Florida Statutes.

The key word is reckless. Vehicular homicide does not require alcohol, drugs, or any intent to hurt anyone. It does require more than a mistake. Reckless driving means driving with willful or wanton disregard for the safety of people or property, the same standard used for reckless driving under section 316.192. A moment of inattention, a misjudged left turn, or ordinary speeding that ends in a death is not automatically vehicular homicide. Our Tampa homicide attorney page explains how we defend every type of homicide charge, including this one.

Fatal crashes are common in Tampa Bay. In 2024, 180 people died in traffic crashes in Hillsborough County, down from 230 in 2023 and 225 in 2022, according to the Florida Department of Highway Safety and Motor Vehicles’ Florida Traffic Crash Facts Annual Report 2024. Statewide that year, 449 people were killed in crashes flagged for speeding or aggressive driving, and 321 of those deaths involved speeding. Most of those crashes never lead to a homicide charge, because the State must prove recklessness, not just a tragic outcome.

What are the penalties for vehicular homicide in Florida?

The base offense is a second-degree felony with a maximum of 15 years in prison and a $10,000 fine. Two circumstances raise it to a first-degree felony with a 30-year maximum.

The failure-to-render-aid enhancement does not require proof that the driver knew anyone was hurt, only that the driver knew or should have known a crash occurred. Trenton’s Law, enacted in chapter 2025-121, Laws of Florida, took effect October 1, 2025. It makes vehicular homicide a first-degree felony when the driver has a prior conviction for vehicular homicide, DUI manslaughter, boating under the influence manslaughter, or vessel homicide.

A conviction also brings a driver license revocation of at least 3 years under section 322.28(4)(a). The court may order 120 hours of community service in a trauma center or hospital that regularly receives crash victims, and courts order restitution to the victim’s family. The 4-year mandatory minimum for leaving the scene appears in section 316.027, not in the vehicular homicide statute, and section 316.027(2)(g) lets the court depart from it in some cases that do not involve impairment. We cover that charge in what is leaving the scene of an accident in Florida.

What must the State prove to convict you of vehicular homicide?

The State must prove three elements beyond a reasonable doubt:

1. Reckless operation of a motor vehicle. The driving must show willful or wanton disregard for safety, not negligence. Most vehicular homicide defenses focus here.
2. Causation. The reckless driving must have caused the death. Another driver running a red light, a mechanical failure, or a road hazard can break that chain.
3. The death of a human being or an unborn child. The medical examiner usually proves this, but the State must still connect the death to the crash rather than to a separate medical event.

Can speeding alone be vehicular homicide in Florida?

In Hillsborough, Pinellas, and Pasco Counties, ordinary speeding alone is not enough. The Second District Court of Appeal, which hears appeals from all three counties, has held that “[s]peed alone will not support a charge of vehicular homicide.” That rule comes from House v. State, 831 So. 2d 1230 (Fla. 2d DCA 2002), where the driver was going about 60 mph in a 30 mph residential zone.

The Second District repeated the rule in State v. Desange, 294 So. 3d 433 (Fla. 2d DCA 2020), a Tampa case from a fatal crash near 40th Street and Lake Avenue. The court said “merely speeding, without any other facts or circumstances demonstrating recklessness as distinguished from negligence, is insufficient.” The court still reinstated the jury’s verdict, because Desange was also weaving through heavy traffic, using turn lanes and bike lanes, sideswiping a car without stopping, and cutting right from the left lane. In Harris v. State, 318 So. 3d 645 (Fla. 2d DCA 2021), the court held that driving 94 mph in a 40 mph zone, standing alone, did not prove reckless driving.

Courts in other parts of Florida have held that grossly excessive speed can be enough by itself:

The Third District summed up the tension in Luzardo: “if there must be a jingle in this area of the law, we would prefer, ‘Speed alone is not enough, except when it is.’” Most recently, the Sixth District affirmed a vehicular homicide conviction in Audinot Lugo v. State, No. 6D2025-1884 (Fla. 6th DCA Aug. 14, 2026), in a short opinion citing Luzardo, Pozo, and Ruiz.

The Legislature responded to the speed-alone gap in 2025 by creating a separate crime of dangerous excessive speeding, which we explain in Florida’s new dangerous excessive speeding crime. Local procedure is covered on our Hillsborough County criminal defense page.

How does the State prove how fast you were going?

The State usually proves speed through some combination of eyewitnesses, police calculations, video, and the car’s event data recorder, often called the black box. Each type of evidence has its own rules.

Black-box data is strong but not perfect. A 2011 National Highway Traffic Safety Administration test of event data recorders in Toyota vehicles, Event Data Recorder: Pre-Crash Data Validation of Toyota Products, found the recorded speeds accurate within about 1.5 mph in low-speed tests, but the data was recorded once per second and could be up to about half a second old. Reconstruction formulas have their own limits. An engineering paper published by SAE International, L. D. Metz and L. G. Metz, Sensitivity of Accident Reconstruction Calculations (SAE Technical Paper 980375, 1998), notes that crash inputs are “almost always” estimated or measured approximately and warns of “the inherent sensitivity of some of the calculations to seemingly small variations in variable magnitudes.”

What did Faustin v. State decide about police speed testimony?

In Faustin v. State, Nos. 4D2024-2667 & 4D2024-2669 (Fla. 4th DCA Oct. 7, 2026), the Fourth District held that a detective’s speed calculation using a “momentum formula” is expert testimony, and it reversed two vehicular homicide convictions because the trial court let the jury hear it without screening it as expert evidence.

Neckson Faustin was convicted in Broward County of two counts of vehicular homicide and one count of reckless driving causing property damage. At trial, Detective Michael Wiley, “a lay witness who acknowledged he was not an accredited accident reconstructionist,” told the jury how fast the vehicles were going “based on his calculation using what he called a ‘momentum formula.’” The trial judge allowed it on the theory that the detective was “merely testifying about his investigation.”

The Fourth District disagreed: “Because Wiley’s calculation depended on specialized knowledge and methodology, it constituted expert opinion testimony subject to section 90.702.” Under section 90.702, which the Florida Supreme Court adopted as Florida’s Daubert standard in In re Amendments to the Florida Evidence Code, 278 So. 3d 551 (Fla. 2019), expert testimony must rest on sufficient facts or data and reliable methods that the witness applied reliably to the case.

The detective’s work failed that test on this record. The court noted that he:

• Used vehicle weights “derived from averages found through internet searches.”
• Calculated departure angles “using Google Maps and a protractor,” while admitting the angles had to be “very accurate.”
• Assumed the Corolla’s approach angle was zero because “[t]hat is how we are taught to do it when we use this formula.”
• Could no longer produce the field sketch behind his calculations.

The State argued the error was harmless because the cars’ event data recorders also showed speed. The court rejected that argument because “testimony established that the data could not be reliably interpreted without independent accident reconstruction.” The detective’s numbers “purported to corroborate that evidence on an issue central to whether the defendant drove recklessly.” The court ordered a new trial.

Faustin does not say that only accredited reconstructionists may testify about speed. It says a formula-based calculation is expert opinion, so the judge must decide whether it is reliable before the jury hears it. The Fourth District reached a similar result in Kemp v. State, 280 So. 3d 81 (Fla. 4th DCA 2019), a vehicular homicide case where a corporal’s opinion from “eyeballing” crush damage failed the reliability test and the court also ordered a new trial. As the Kemp court put it, “repeated invocation of the magic words ‘training and experience’ was insufficient.”

Faustin is a Fourth District decision. Trial courts in Tampa Bay follow other districts’ decisions when the Second District has not ruled otherwise, and the section 90.702 standard applies statewide.

The challenge to police speed math can be raised at three points: in a pretrial motion asking the judge to hold a reliability hearing, by objection at trial, and on appeal if the judge lets unreliable testimony in. Losing at one stage does not end the issue at the next.

How do our attorneys defend vehicular homicide charges?

We attack the two elements the State most often overreaches on, recklessness and causation, with independent expert work rather than argument alone. Our defense in these cases typically includes:

1. An independent reconstruction. Our expert reviews the scene measurements, crush damage, video, and black-box data before the State’s version hardens.
2. Reliability challenges to State experts. Under Faustin and Kemp, we ask the court to screen speed and braking opinions before the jury hears them. Our Tampa criminal forensic science attorney page explains how we work with experts.
3. Suppression of black-box data. If police downloaded the event data recorder without a warrant or a real emergency, we move to suppress it under Worsham.
4. Mechanical and other causes. ASE-certified mechanics inspect for brake failure, tire failure, and steering defects, and we investigate the role of other drivers and road conditions.
5. The speed-alone rule. In our district, the State must prove more than speed. We hold it to House, Desange, and Harris.

Past results do not guarantee future outcomes. We tell the full story in When the Car, Not the Driver, Caused the Crash.

What should you do if you are under investigation after a fatal crash?

Talk to a lawyer before you give any statement. Vehicular homicide charges are often filed weeks or months after the crash, while the traffic homicide investigator waits for toxicology, downloads the event data recorders, and reconstructs the scene. In the 13th Judicial Circuit, fatal crashes are assigned to traffic homicide investigators from the Florida Highway Patrol, the Hillsborough County Sheriff’s Office, or the Tampa Police Department.

There is no deadline that protects you by running out. Under section 775.15(1), “a felony that resulted in a death may be commenced at any time.”

That investigation window is when a defense expert can still photograph the scene, inspect the vehicles before they are released or repaired, and preserve electronic data. What you say to the investigator, even to explain, often becomes the recklessness evidence. Our pre-file advocacy work manages contact with law enforcement and gets preservation demands out early. Our guide to whether the Florida accident report privilege requires you to talk to police after a crash explains what you must tell an officer and what you can decline.

For more about our defense strategies, visit our Homicide Defense page.

Frequently asked questions about vehicular homicide in Florida

Can police use my car’s black box data without a warrant in Florida?

Not usually. In State v. Worsham, the Fourth District held that police need a warrant to download event data from an impounded car unless an emergency exists. The Brancato Law Firm checks how and when the black box was downloaded in every fatal crash case.

Does a traffic homicide investigator have to be an accredited reconstructionist to testify about speed?

Faustin v. State (2026) did not require accreditation, but it held that a formula-based speed calculation is expert testimony. Under Faustin, the judge must decide whether the method is reliable and was applied reliably before the jury hears it. Our attorneys at The Brancato Law Firm file those challenges before trial so the issue is decided on a full record.

Can a witness testify about how fast they think I was driving?

Yes, if the witness had a real opportunity to observe. Florida courts treat a speed estimate as common observation, but the estimate must rest on what the witness actually saw. The Brancato Law Firm investigates each eyewitness’s vantage point, lighting, and distance to test that estimate.

Is there a statute of limitations for vehicular homicide in Florida?

No. Section 775.15(1) allows prosecution of “a felony that resulted in a death” at any time. Because charges can come months later, The Brancato Law Firm begins preserving evidence as soon as a client calls.

Can vehicular homicide charges be dropped or reduced in Florida?

Yes, when the recklessness or causation evidence is weaker than the tragedy suggests. A charge can be reduced to reckless driving when the defense shows negligent rather than reckless driving, or dropped when an independent cause produced the death. The Brancato Law Firm builds those arguments on independent expert analysis, as our Tampa criminal traffic lawyer page describes for reckless driving cases.

What is the difference between vehicular homicide and DUI manslaughter?

Vehicular homicide requires reckless driving but no impairment, while DUI manslaughter requires impairment or an unlawful alcohol level but no recklessness. Prosecutors sometimes charge both from the same crash. Our attorneys at The Brancato Law Firm explain the differences in our guide to DUI manslaughter in Florida.

Does Trenton’s Law make a second vehicular homicide a first-degree felony?

Yes. Since October 1, 2025, section 782.071(1)(c) makes vehicular homicide a first-degree felony when the driver has a prior conviction for vehicular homicide, DUI manslaughter, boating under the influence manslaughter, or vessel homicide. The Brancato Law Firm examines every prior conviction the State relies on to confirm it actually qualifies.

Is vessel homicide treated the same way?

Yes. Section 782.072 applies the same penalty structure to deaths caused by reckless operation of a boat. Our attorneys at The Brancato Law Firm defend vessel homicide charges with the same expert-driven approach, adding the navigation rules and wake conditions that replace lanes and traffic signals on the water.

Talk to a Tampa criminal defense attorney after a fatal crash

If you or a loved one is under investigation or has been charged after a fatal crash in Hillsborough, Pinellas, or Pasco County, the attorneys of The Brancato Law Firm, P.A., founded by Tampa Criminal Defense Attorney Rocky Brancato, can get an independent reconstruction started now. Call (813) 727-7159 before you speak with the traffic homicide investigator. Vehicles get released, data gets overwritten, and scenes get repaved.

The Brancato Law Firm, P.A.
620 E. Twiggs Street, Suite 205, Tampa, FL 33602
(813) 727-7159
Serving Hillsborough, Pinellas, and Pasco Counties

The Brancato Law Firm, P.A. is a Tampa-based criminal defense practice. We are not affiliated with any other Brancato-named law firms.

When a high-speed crash kills a passenger, prosecutors typically assume the driver is at fault. After all, they look at the speed, the damage, and the witness statements—and then they charge vehicular homicide.

However, sometimes the driver is not at fault. In certain cases, the vehicle itself is the cause. A stuck accelerator, a brake failure, or a mechanical defect—any of these can turn an ordinary drive into an uncontrollable disaster.

Consequently, proving mechanical failure requires more than a typical accident reconstructionist. Instead, it requires someone who can analyze both the crash dynamics and the vehicle itself. In this case, an expert who combined accident reconstruction expertise with ASE mechanic certification found the evidence that changed everything. 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 Fatal Crash and a Grieving Friend

My client was driving with his friend as a passenger when his vehicle crashed into a tree at high speed. Tragically, the impact killed his friend instantly.

Before the crash, neighbors heard the engine roaring. Subsequently, police measured the damage, estimated the speed, and concluded that my client had driven recklessly. As a result, they charged him with vehicular homicide.

However, my client told a different story. According to him, the accelerator got stuck. No matter what he did, he could not slow down. The crash was not his fault—it was the car’s.

The question was whether we could prove it.

The Prosecution’s Theory: Reckless Driving

The state built a straightforward case based on three key points:

• First, neighbors heard the engine roaring—which they cited as evidence of excessive speed
• Second, the vehicle struck a tree at high velocity—which they presented as evidence of loss of control
• Third, a passenger died in the crash—the tragic result that the prosecution attributed to the driver’s conduct

To the prosecution, therefore, the conclusion seemed obvious: the driver was speeding, lost control, and killed his passenger. In their view, this constituted vehicular homicide.

Nevertheless, the prosecution never examined the vehicle itself. Instead, they assumed driver error without investigating whether mechanical failure could explain what happened.

The Expert: Two Disciplines in One

To challenge the prosecution’s theory, I retained an expert with a unique combination of qualifications: he was both an accident reconstructionist and an ASE-certified mechanic.

This combination proved critical for our defense. While a typical accident reconstructionist can analyze crash dynamics—speed, impact angles, and vehicle trajectories—proving mechanical failure requires someone who can also get under the hood and identify what went wrong with the vehicle itself.

The Investigation: Examining What the Police Ignored

My expert conducted a comprehensive examination of the vehicle. Rather than simply looking at the crash damage, he examined the mechanical systems that controlled acceleration and braking.

His findings proved significant: the vehicle had issues with the accelerator that caused it to get stuck.

Importantly, this conclusion rested on physical evidence from the vehicle itself—not speculation. Moreover, this represented evidence that the prosecution had never bothered to examine.

What the Expert’s Findings Meant

The stuck accelerator explained everything about this crash:

• It explained why neighbors heard the engine roaring—because the accelerator was stuck open
• It explained why the vehicle traveled at high speed—because the driver could not reduce power to the engine
• It explained why my client lost control—because he was fighting a vehicle that would not respond to his inputs
• It explained why braking alone could not prevent the crash—because with the accelerator stuck, the engine continued producing power even as the driver tried to stop

In other words, my client did not drive recklessly. Instead, he became a passenger in his own vehicle—trapped behind the wheel of a machine that had malfunctioned and would not obey his commands.

The Impact on the Case

The expert’s findings fundamentally changed the nature of the case. As a result, this was no longer a simple vehicular homicide prosecution based on reckless driving. Instead, there was now credible evidence that mechanical failure—not driver misconduct—caused the crash.

Consequently, the prosecution faced a difficult choice: take the case to trial and risk a jury believing the mechanical failure defense, or negotiate a resolution that reflected the true nature of what happened.

Types of Mechanical Failures That Can Cause Crashes

What This Case Teaches About Vehicular Homicide Defense

• First, do not assume the driver is at fault. High-speed crashes can result from mechanical failure, not just reckless driving. Therefore, the vehicle itself must be examined.
• Second, retain an expert who can perform both crash analysis and mechanical inspection. An accident reconstructionist who also holds mechanic certification can connect the crash dynamics to the mechanical failure.
• Third, preserve the vehicle immediately. If mechanical failure is a potential defense, the vehicle must remain intact for expert examination. Once someone destroys or repairs it, the evidence disappears.
• Fourth, challenge the prosecution’s assumptions aggressively. Prosecutors often assume driver error without investigating alternatives. Consequently, a thorough defense investigation can reveal evidence they missed.
• Finally, understand that mechanical failure can transform the entire nature of the case. What initially looks like reckless driving may actually represent a driver fighting to control a malfunctioning vehicle.

Frequently Asked Questions

Facing Vehicular Homicide Charges?

A fatal crash does not automatically mean the driver bears fault. After all, mechanical failures happen—and when they do, the driver may have had no ability to prevent the tragedy.

For over 25 years, I have defended clients against serious charges throughout Tampa Bay. As a result, I know how to investigate what really caused a crash, retain qualified experts who can examine both crash dynamics and mechanical systems, and present evidence that challenges the prosecution’s assumptions.

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

Related Case Studies: DNA Evidence Defense | Aggravated Child Abuse Defense | Forensic Pathologist | Fingerprint Evidence is Not as Reliable as You Think | Cell Phone Location Data Can prove You Were Not There | When Brain Damage Explains Criminal Conduct | Your BAC at the Station is Not Your BAC Behind the Wheel | When Police Destroy Evidence They Do Not Get the Benefit of the Doubt | When a Confession is Not a Confession | The Injuries Were Real–But They Were Not From the Alleged Rape | Similar Is not The Same: How a Firearms Expert Kept Out Prejudicial Evidence

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