Obtaining and Admitting Evidence from a Vehicle’s Black Box

The number of people killed in motor vehicle crashes in the United States increased in by 5.6 percent from 2015 to 2016. In 2016, 37,461 people were killed in crashes on U.S. roadways, compared to 35,485 the previous year. North Carolina’s fatality figures followed the national trend, with fatalities increasing from 1,379 in 2015 to 1,450 in 2016, a 5.1 percent increase. Many such fatalities result in criminal vehicular homicide charges, which number in the hundreds each year in North Carolina alone.

Investigators and prosecutors in such cases are increasingly relying upon the vehicle itself to tell the story of what happened during and just before the crash. Many vehicles driven today (and nearly all manufactured in the past five years) are equipped with an Event Data Recorder (EDR) installed by the manufacturer. An EDR, often referred to as a car’s black box, contains data related to various aspects of the car’s operation seconds before a crash, including its speed, whether the brakes were applied, and the position of its gas pedal. This kind of evidence can play a central role in the State’s attempt to show culpably negligent driving. But how may the State lawfully obtain EDR information? And, once obtained, how may it be introduced into evidence?

Backgrounds on EDRs. EDRs are “tiny microcomputer chip sets” that are generally part of a vehicle’s airbag control system. See Michelle v. Rafter, Decoding What’s in Your Car’s Black Box, (last updated 7/22/2014). Indeed, EDRs were initially designed to ensure that airbags deployed when they should. Today, they do more than monitor airbags. Federal regulations now require that EDRs record fifteen types of data, including a vehicle’s speed, its engine throttle or the position of its accelerator pedal, whether the driver is wearing a seat belt, the “delta-V” (meaning the cumulative change in velocity during a crash event), and whether the brake pedal was pressed. See 49 C.F.R. § 563.7.

Data collected by an EDR is stored in temporary memory, where it is continuously updated and overwritten at regular intervals. If a car’s airbags deploy, however, the EDR writes information into permanent memory that can be retrieved after the crash. See Commonwealth v. Safka, 95 A.3d 304 (Pa. Super. 2014), affirmed, 141 A.3d 1239 (Pa. 2016). The saved data includes information from up to five seconds immediately before, during, and after the crash. See Rafter, supra. To extract EDR data, a cable is connected to the EDR’s diagnostic port. See State v. Worsham, 227 So.3d 602 (Fla. Dist. Ct. App. 2017). The extracted data may subsequently be interpreted by a person who understands EDR technology and data. Id.

EDRs, unlike the black boxes in aircraft, do not record audio (or, for that matter, video) data from the vehicle.

Who owns the data collected by an EDR? Congress declared in the Driver Privacy Act of 2015 that EDR data is the property of the vehicle’s owner, or, the case of a leased vehicle, the lessee. The 2015 legislation provides that EDR data may be accessed by a person other than the owner or lessee in five circumstances: (1) pursuant to a court or administrative order, (2) with the consent of the owner or lessee, (3) pursuant to an investigation of a motor vehicle accident by the Secretary of the Treasury or the National Transportation Safety Board, provided personally identifiable information is not disclosed, (4) for the purpose of emergency medical response to a vehicle crash, or (5) for traffic safety research, provided personally identifiable information is not disclosed.

How may EDR data be obtained in connection with a criminal investigation? A law enforcement officer investigating a motor vehicle crash obviously can obtain EDR data pursuant to a search warrant supported by probable cause. But is such a search warrant required? State courts have disagreed about that.

The District Court of Appeal for Florida held in State v. Worsham, 227 So.3d 602 (Fla. Dist, Ct. App. 2017), that a vehicle owner has a reasonable expectation of privacy in the data maintained by an EDR. Thus, the court held that law enforcement officers violated the Fourth Amendment when they downloaded EDR data from Worsham’s impounded vehicle without a warrant. The court reasoned that the data recorded by an EDR is not exposed to the public and is difficult to extract and interpret. Thus, it held that absent exigent circumstances, a law enforcement officer must obtain a warrant before extracting EDR data from an impounded vehicle.

The California Court of Appeal took a different view in People v. Diaz, 153 Cal.Rptr.3d 90 (Cal. App. 4th 2013). Members of the California Highway Patrol’s accident investigation team inspected the defendant’s totaled vehicle in their impound lot more than a year after she was involved in a crash that killed another motorist. Part of the physical inspection of the vehicle included downloading its EDR information. The officers did not seek a court order before doing so; downloading EDR data was part of their standard protocol for a mechanical inspection.

There was no question as to whether the search of Diaz’s vehicle was supported by probable cause―the question before the court was whether a warrant was required. The court determined that it was not. The court reasoned that the specific data obtained from the EDR, namely the speed of the defendant’s vehicle and whether the defendant braked before impact, was not information in which she had a reasonable expectation of privacy. The speed of a vehicle on a public highway may be readily observed and measured, the court explained. In addition, vehicles are required to have brake lights which announce to the public when the brakes are applied. Thus, the EDR merely captured information the defendant knowingly exposed to the public.

How may EDR evidence be admitted at trial?  An expert witness is likely required to both interpret and establish the reliability of EDR data given that the functioning of an EDR system and the interpretation of the data it collects are beyond the ken of the average juror. Several courts have deemed EDR evidence sufficiently reliable and admissible when accompanied by testimony from such an expert. See, e.g. Matos v. State, 899 So.2d 403 (Fla. Dist. Ct. App. 2005) (trial court did not err in admitting EDR evidence through two experts, an accident reconstructionist trained in EDR technology, and an industrial engineer who was the chairman of the Society of Automotive Engineers); Easter v. State, 115 A.2d 239 (Md. App. 2015) (trial court did not err in admitting EDR evidence provided by law enforcement officer who was qualified as an expert in accident reconstruction); Commonwealth v. Zimmermann, 873 N.E.2d 1215 (Mass. App. 2007) (affirming admission of EDR evidence provided by expert in accident reconstruction, who had taught courses in accident reconstruction, had published in the field, and had participated in almost 1,000 crash tests); State v. Shabazz, 946 A.2d 626 (N.J. Super. 2005) (granting State’s motion to introduce EDR data based on testimony from expert in accident reconstruction and EDR devices who had conducted crash tests and worked with automotive engineers); Safka, 95 A.3d 304 (trial court did not err by admitting EDR testimony from retired electrical engineer employed by Ford Motor Company for 33 years).

Is EDR data being used in NC? Our appellate courts have not yet decided a case involving the obtaining or admission of EDR evidence. That does not mean, of course, that this kind of evidence isn’t being used in crash investigations or at trial.  Have you litigated a case involving EDR? Send in a comment and let us know how it turned out.

2 thoughts on “Obtaining and Admitting Evidence from a Vehicle’s Black Box”

  1. I tried a case with EDR data from the victim’s vehicle. The judge found no admissibility issues with the law enforcement officer qualified as an expert in crash reconstruction, who was specifically trained to use a program called FARO who input the data and interpret the results of the data points. Incidentally, a big issue at trial was that my client’s vehicle also had an EDR and the State failed to retrieve my client’s EDR info, only that of the victim. He was convicted, in large part, due to the animation created by the expert on that FARO software using data only from the victim’s vehicle.


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