by David Daggett

When investigating a fatal or life-threatening injury collision, it has pretty much become standard practice for law enforcement to download the data from the “little black box,” or Event Data Recorder, should the vehicle be so equipped. The information contained therein can be of utmost assistance to police and prosecutors in helping prove their case. This month’s blog focuses on possible legal challenges surrounding the gathering of that data.

A fairly large percentage of vehicles manufactured in the past five to eight years come equipped with an Event Data Recorder of some type. Depending on the year, make and model, these devices may include data such as vehicle speed prior to impact, speed at impact, acceleration/deceleration, accelerator pedal position, engine torque, cruise control status, the seatbelt status of driver and passengers, airbag deployment, braking efficiency, steering angle, time, distance and velocity measurements at various points prior to impact, principle direction of force, as well as other information that might be of importance to your case. This data can be used to help corroborate witness statements, discredit the defendant’s statements or substantiate your collision reconstructionist’s findings.

The first such devices were installed in automobiles in 1974 as a result of a National Highway Traffic Safety Administration (NHTSA) project designed to study driving habits and improve vehicle safety. The number of devices rapidly increased with the advent of mandatory air bags. These initial sensing diagnostic modules (SDMs) were designed to control air bag deployment and gather information about the vehicle’s operation just prior to deployment. Modern EDRs contain short snippets of data, usually between 5-10 seconds long, which are constantly replaced and updated with new data. When a crash occurs, the EDR preserves the period of data leading up to impact and provides detailed information of what was happening during that brief period.

How helpful that information can be will obviously start and end with its admissibility at trial. As Maryland’s appellate courts (and Legislature) have not yet addressed the issue, this article will primarily focus on Frye-Reed and Fourth Amendment challenges.

Frye – Reed Challenges

It has been the law of Maryland since 1978 that, before a scientific opinion will be received as evidence at trial, the basis of that opinion must be shown to be generally accepted as reliable within the expert’s particular scientific field. See Reed v. State, 283 Md. 374 (1978). According to standard set forth in Frye v. United States, 293 F. 1013 (1923), if a new scientific technique’s validity is in controversy in its relevant scientific community, or if it is generally regarded as an experimental technique, then expert testimony based upon its validity cannot be admitted into evidence. Before addressing whether an expert’s opinion is generally accepted in the relevant scientific community, the court must first determine whether that opinion/evidence is scientific, new or novel. If the court finds that the evidence is both scientific and new or novel, it must then determine whether that technique has gained general acceptance in the scientific community. If so, it may be admitted into evidence, but only if the trial judge also determines that the proposed testimony will be helpful to the jury and that the expert is properly qualified.

While Maryland has not yet faced a Frye-Reed challenge on the EDR, a number of other jurisdictions have. In Matos v. State, 899 So. 2d 403 (2005) the Florida Appellate Court addressed the issue:

The process of recording and downloading SDM (sensing diagnostic modules) data does not appear to constitute a novel technique or method…Crash sensors such as the SDM have been in production in automobiles for over a decade, and the microprocessors that run them and record their data also run everyday appliances, such as computers and televisions.

In Bachman v. General Motors, 332 Ill. App. 3d 760, 776 N.E. 2d 262 (2002), the Illinois Appellate Court, using the Frye test, stated that the trial court did not abuse its’ discretion by finding that the process of recording and downloading SDM data is sufficiently established to have gained general acceptance in the relevant scientific community and that the Frye admissibility standard had been satisfied.

The Massachusetts appellate court, using a modified Daubert formula in the case of Commonwealth v. Zimmerman, 70 Mass. App. Ct. 357, 873 N.E. 2d 1215 (2007) concluded that the trial judge did not abuse his discretion in allowing Event Data Recording information to be presented in court. Massachusetts requires the proponent to show that the underlying scientific theory is generally accepted within the relevant scientific community, or by showing that the theory is reliable or valid through other means.

Other states have also found EDR evidence to be reliable, including New Jersey, in State of New Jersey v. Shabazz, 400 N.J. Super. 203, 946 A.2d 626 (N.J. Super. Ct. Law Div. 2005); New York, in People v. Slade, 2005 N.Y. Misc. Lexis 3217, 233 NYLJ 11 (2005); and Louisiana, in Laborde v. Shelter Mut. Ins. Co., 80 So. 3d 1 (2011) (Overturned on other grounds.)

In Shabazz, a New Jersey trial court determined the scientific reliability of event data recorder evidence was generally accepted within the automotive and collision reconstruction community. In Slade, a New York court held that the technology upon which the SDM and EDR is based dates back to the 1980’s. The court stated that, “aside from the automobile industry, the same type of recording technology has been used in aviation, cruise ships, cargo ships and trains. The technology involved has been relied upon for years. In the field of aviation, event data recorders, called “flight data recorders” have been used since the 1940’s. The information…has been relied on for years by the government that regulates air bag safety, vehicle manufacturers in making safer air bag systems and crash researchers and reconstructionists.” Slade @ 13. In Laborde, the Court of Appeals of Louisiana held that recording or downloading from the box is not novel and has been used in the automobile industry for over ten years.

Clearly, there is nothing new or novel about this evidence. The sensors in these devices have been in production for decades and the microchips and microprocessors that control and download the data are no different from those that run our computers, cellphones, I pads, televisions and other appliances.

Fourth Amendment Challenges

We are all familiar with the language of the Fourth Amendment:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, an no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

The Fourth Amendment only protects against unreasonable searches and seizures and a search is presumed to be unreasonable unless it falls within one of the well-delineated exceptions to the warrant requirement. While the list of exceptions seems to be constantly expanding, at last check there was no specific exception for EDR data searches. Of course, an argument could be made that such a search would fall within the other exceptions. Let’s take a look at some of them:

  • Consent Search – As long as the consent obtained was knowing, freely and voluntarily given, such a search should be valid. If the suspect is not under arrest and is free to leave (though not to leave in the vehicle) then consent should be upheld. If the suspect was seriously injured in the crash, no doubt the defense will likely try and argue that his consent wasn’t “knowing.” Just remember, when seeking consent, it is always better to get it in writing.
  • Search incident to a lawful arrest – In most automobile crashes, especially those involving collision reconstruction, a fatality and/or a life-threatening injury, it is usually recommended that the defendant not be issued any payable citations, and in many cases the suspect might not even be arrested until the investigation is fully completed. Occasionally, the suspect is placed under arrest for driving while impaired or under the influence of alcohol. In those cases, does a seizure of the EDR amount to a valid search incident to arrest? Would a seizure and subsequent search of the black box be permissible under the holding of Arizona v. Gant? There are some state cases that have upheld such a warrantless search and others that have not. Maryland has not ruled on the issue.

On the other hand, a number of states have enacted EDR statutes (appx. 15, including Virginia, but not Maryland ) and most of them require that law enforcement seek a warrant or court order prior to seizing and analyzing the data. While those statutes are not binding on the issue, they could be compelling.

  • Automobile Exception – The United States Supreme Court, going back to Carroll v. United States (see August 2014 Blog), has held on numerous occasions that one’s expectation of privacy is greatly diminished in an automobile. Many of the rulings in those types of cases involve probable cause on the part of the police to believe the vehicle contained “contraband.” Conversely, the Supremes have also recognized some legitimate expectations of privacy in vehicles deserving of protection. See Arizona v. Gant, 556 U.S. 332 (2009); United States v. Ortiz, 422 U.S. 891 (1975). Certainly, the data located in an EDR is not “contraband.” Does the driver of the vehicle have an “expectation of privacy” in the information contained therein? Maybe yes and maybe no. Certainly a valid argument can be made supporting both sides of the issue. If you’re interested in further researching the issue, see the following state cases: People v. Christmann, 776 NYS 2d 437 (2004); People v. Slade, 2005 N.Y. Misc. Lexis 3217, 233 NYLJ 11 (2005); People v. Diaz, 213 Cal. App. 4th 743 (2013); State v. Holladay, 2006 Tenn. Crim. App. Lexis 152, 2006 WL 304685 Westlaw), unreported; People v. Xinos, 192 Cal. App. 4th 637 (2011). Some of them upheld the warrantless searches; some suppressed the evidence.
  • Exigent Circumstances – If evidence of the pre-collision condition of the suspect’s vehicle could possibly be destroyed due to the automobile being moved from the scene, exigency would likely justify the downloading of the data prior to securing a search warrant. A warrant should be obtained before reading the data, however.
  • Inventory Search – While officers, pursuant to a departmentally approved inventory search, may conduct warrantless searches of seized property to both protect the person’s property and protect officers against claims of stolen or lost items, it would be quite the stretch to argue that this applied to the data stored in the EDR.


After consulting with many of my colleagues from across the country, it is our unanimous opinion that the prudent course of action is to always obtain a search warrant prior to downloading data from a suspect’s vehicle’s EDR. The sole exception would be if there is danger of the data being lost due to the vehicle being moved, towed or loaded onto a flatbed. In those situations, you would probably be on solid legal ground by downloading the data prior to moving the vehicle but not in looking at it until a warrant has been secured.

When securing such a warrant, remember that Rule §5-601 and Criminal Procedure Article §1-203 require that a search and seizure under the authority of a search warrant be made within 15 calendar days from the day the warrant was issued.

As always, please consult with your local State’s Attorneys’ Office with any questions regarding issues raised in this article.