Revisiting Criminal Culpability Under the Clean Air Act in the Wake of ‘Dieselgate’

October 9, 2018 by Spencer Shweky

Cars in traffic on a highway near a body of water

It has now been just over 3 years since the Environmental Protection Agency (“EPA”) first informed the public that Volkswagen, at the time the world's largest automaker, had installed ‘cheat devices’ designed to evade U.S. regulators in hundreds of thousands of their cars. Ultimately, the automaker paid a $2.8 billion criminal fine, and 9 executives and employees were charged with violating the Clean Air Act (“CAA”) and Title 18 of the United States code (the main criminal code of the federal government). Interestingly, though, no one was actually held criminally liable for the pollution itself.

In the spring of 2014 engineers at West Virginia University conducted a study on “In-Use Emissions Testing of Light-Duty Diesel Vehicles in the United States.”[1] The study was designed to analyze the gap between real world emissions and regulatory certification levels, ostensibly to demonstrate the superiority of United States  emissions regulations compared to less stringent European standards.[2] Accordingly, the engineers conducted their tests while the vehicles were “on road” under normal operating conditions.[3] In doing so, they were shocked to discover that two Volkswagen models, the Passat and the Jetta, were emitting nitrogen oxides (“NOx”) at values far above that which is permissible under CAA emissions standards.[4] The engineers subsequently informed Volkswagen and the EPA, touching off the investigation, litigation, and prosecution that would collectively come to be called ‘Dieselgate.’[5] 

In the months that followed, Volkswagen repeatedly attempted to mislead agency officials by providing false or otherwise deceptive explanations.[6]Then, in the summer of 2015, a lone Volkswagen employee disclosed to regulators that the cars contained a cheat device, and the company subsequently admitted as much (at least with respect to their 2.0-liter vehicles.[7]Shortly thereafter, the EPA issued its first Notice of Violation, which revealed for the first time that approximately 500,000 2.0-liter diesel passenger cars sold in the United States contained an emission control-evading software.[8] The following November, after EPA had conducted additional testing designed to detect cheat devices, a second Notice of Violation was issued, this time revealing that an additional 90,000 3.0-liter Volkswagen vehicles contained software similar to that which had been discovered in the 2.0-liter vehicles.[9]

Ultimately, the company ended up pleading guilty to three felonies, and paid out $4.3 billion in criminal and civil penalties.[10]The $2.8 billion criminal fine was the largest ever imposed by U.S. authorities on an automaker.[11]In addition, nine executives and employees of Volkswagen have been charged, including, most recently, the former CEO of Volkswagen, Martin Winkerton.[12]

While in some sense this outcome may be appropriately lauded as a landmark achievement for criminal enforcement of the Clean Air Act (“CAA”), it is worth noting that neither the company nor any of its agents were actually charged with knowingly violating the emissions requirements of the CAA.[13]Instead, they were charged with making false statements, conspiracy, and obstruction of justice under Title 18 of the United States code and the CAA.[14]This is because the CAA  exempts ‘mobile source’ violators from criminal culpability for emissions violations.[15]

Some might argue that this is just as well. Criminal culpability for environmental violations has long been controversial, not least because the ‘knowing’ mens rea requirement in most environmental statutes (the CAA among them) appears to some to be unduly harsh on polluters.[16]Under the ‘knowing’ standard, a defendant may be held criminally liable for mere awareness of the facts constituting the crime (conscious intent is not required, nor is knowledge of the law).[17] Under such circumstances, it does seem unfair that some might be subjected to criminal sanctions for accidentally failing to comply with what are admittedly fairly complex regulations.

On the other hand, it seems equally unjust that a multinational company like Volkswagen might have been able to evade culpability had they simply been less heavy handed in their attempted cover-up, or otherwise been more successful in pinning the blame on low-level employees. After all, the illegal pollutants discharged by their non-compliant vehicles did real, irreversible damage- by one count, the extra pollution in Volkswagen’s U.S. 2.0-liter cars alone might have resulted in up to 27 premature deaths annually.[18] Providing for criminal liability for such crimes would certainly raise the stakes for would-be violators, especially since the ‘knowing’ mens rea would all but insure conviction upon discovery of a violation. Under such circumstances, it is tempting to think that violations might be less frequent.

To be sure, there are merits to both arguments. All the same, this is a debate that policymakers and activists alike should be tuned in to in the years ahead.

[1] John C. Cruden et al., Dieselgate: How the Investigation, Prosecution, and Settlement of Volkswagen’s Emissions Cheating Scandal Illustrates the Need for Robust Environmental Enforcement, 36 Va. Envtl. L.J. 118, 123 (2018).

[2] Id.

[3] See Id. at 123-24.

[4] Id.

[5] See Id. at 124.

[6] Id.

[7] Id. at 125.

[8] Id.

[9] Id. at 128-29.

[10] Dep’t of Justice, Volkswagen AG Agrees to Plead Guilty and Pay $4.3 Billion in Criminal and Civil Penalties; Six Volkswagen Executives and Employees are Indicted in Connection with Conspiracy to Cheat U.S. Emissions Tests (2017),

[11] Paula A. Eisenstein, Volkswagen Slapped With Largest Ever Fine for Automakers, NBC News (April 21, 2017, 12:33 PM),

[12] Dep’t of Justice, Former CEO of Volkswagen AG Charged with Conspiracy and Wire Fraud in Diesel Emissions Scandal (2018),

[13] Indictment, UNITED STATES OF AMERICA, v. D-2 Richard DORENKAMP, D-3 Heinz-Jakob Neusser, D-4 Jens Hadler, D-5 Bernd Gottweis, D-7 Jurgen Peter, and D-9 Martin Winterkorn, Defendants., 2018 WL 3127224 (E.D.Mich.); Complaint, UNITED STATES OF AMERICA, Plaintiff, v. VOLKSWAGEN AG, Audi AG, Volkswagen Group of America, Inc., Volkswagen Group of America Chattanooga Operations, LLC, Dr. Ing. H.c. F. Porsche AG, and Porsche Cars North America, Inc., Defendants., 2016 WL 25162 (E.D.Mich.).

[14] Id.

[15] See Arnold W. Reitze Jr., The Volkswagen Air Pollution Emissions Litigation, 46 Envtl. L. Rep. News & Analysis 10564, 10567 (2016).

[16] See generally David M. Uhlmann, Prosecutorial Discretion and Environmental Crime, 38 Harv. Envtl. L. Rev. 159 (2014).

[17] See Model Penal Code §2.02 (Am. Law Inst. 2017); David M. Uhlmann, Prosecutorial Discretion and Environmental Crime,38 Harv. Envtl. L. Rev. 159, 169 (2014).

[18] Brad Plumer, How many deaths did Volkswagen’s pollution scandal cause?, (Sept. 24, 2015, 8:58 AM),