Amicus Brief Offers History of Habitual Criminal Laws and Their Origins

interior of the Colorado Supreme Court
The interior of the Colorado Supreme Court.

Clinical Lecturer in Law Daniel Loehr has filed an amicus brief in a major case before the Colorado Supreme Court. The brief emerged from historical work that he conducted while at Yale Law School with the support of Research Assistants Balen Essak-Hernandez ’25 and Courtney Perales ’25 and librarians from the Lillian Goldman Law Library. 

The case involves Colorado’s habitual criminal law and implicates hundreds of people in Colorado prisons. Loehr’s brief offers a history of the habitual criminal law, and specifically argues that the law emerged from the eugenics movement. 


The underlying case, which is co-counseled by Gail Johnson ’96 and the Spero Justice Center, involves a man who was sentenced to life in prison in 1996 under Colorado’s habitual criminal law. Habitual criminal laws impose exponentially greater penalties for people with prior convictions. The petitioner argues that a recent Colorado Supreme Court opinion, Wells-Yates v. People, is retroactive, and thus allows him and others similarly situated to seek review of their sentences. 

Wells-Yates established rules to limit the state’s power to impose the harshest habitual criminal punishments and urged courts to review sentences by looking to Colorado’s evolving standards of decency. The State of Colorado takes the position that Wells-Yates is not retroactive and thus that the petitioner has no right to sentence review.

Because Wells-Yates trained its attention on evolving standards of decency, Loehr’s amicus brief provides the historical context of Colorado’s habitual criminal law to show what has changed since it was enacted. In particular, the brief documents the eugenic roots of habitual criminal laws and how they were premised on the belief that so-called “habitual criminals” were an inferior subspecies that should be prevented from reproducing. 

The brief states that Colorado’s first “habitual criminal law” was passed in 1929 and emerged directly from the eugenics movement of the early 20th century, which understood “criminality” to be a heritable trait.

“Some of the habitual criminal statutes were passed around the same time as forced sterilization laws,” said Perales. “Both sets of laws used similar language to describe people who committed repeat offenses as inherently criminal and lacking morals and were influenced by eugenics ideologies of the times.”

Loehr adds in the brief that, “to stop the spread of ‘criminality’ from one generation to the next, eugenicists sought to identify those who were innately criminal, and then incapacitate them for their reproductive years — by sterilization, by marriage restrictions, and, as is often overlooked, by the passage of habitual criminal laws.” 

Essak-Hernandez said that the research demonstrated the lasting impact of the eugenics movement.

“Racist ideas from the eugenics movement that have long been disproven and debunked still pervade the criminal justice system and lengthen sentences for criminal defendants,” he said.

To uncover this history, Loehr, Essak-Hernandez, and Perales looked at over a century of habitual criminal laws across the country using Law Library databases and other resources. 

“This was an important step to identify different variations and if the statutory language changed over the years,” said Perales. “We also researched state libraries and digital newspaper archives to find references to the habitual criminal laws or of public discourse around implementing one.”

The team traced current habitual criminal laws back in time by finding every instance when a law was amended. The result is an appendix showing habitual criminal laws in all 50 states and the District of Columbia and their history.

The process takes time. While some information is available online, much is not.

“Many of the sources are either not fully digitized or not searchable even if they are digitized,” Essak-Hernandez said. “I got a bit more efficient finding relevant information the more research I did, but it is still a time-consuming endeavor.”

The team had the help of John Nann, Senior Librarian for Research, Instruction, and Collection Development at the Lillian Goldman Law Library. Nann showed Loehr and the students how to conduct historical state statute research and develop a system for tracing the statutes’ development. 

“Online databases are constantly growing, but Yale Law School has access to a wide breadth of sources that are only available in print. I am so used to everything being available on Google, Lexis+, or Westlaw that I often forget to check for a hard copy of an important and otherwise-unavailable source,” Essak-Hernandez said.

Loehr also relied on historical books sourced from libraries across the country. “Alison Burke and the whole library staff worked diligently and quickly to find out-of-print books and articles from a century ago,” Loehr said. 

The research process taught the team two important lessons, according to Loehr. First, they learned how historical state statutes are organized and published, and where to find them—a useful skill for all lawyers trying to understand the history and context of a particular statute. State libraries, Perales said, are a key resource for statutory archives.

“Second, we learned that contemporary understandings of statutes may obscure a more complicated past and that the only way to fully understand the historical context of a law that is affecting a client today is to trace it back to its origins,” Loehr said.

Essak-Hernandez said he hopes the research and the resulting amicus brief will force policy makers to reexamine the habitual criminal laws still on the books.

“Many states have apologized for laws they passed based on eugenics,” he said. “Those apologies, though, have not included habitual offender sentencing laws. I believe it’s long past time for states to repeal the cruel habitual offender laws that sentence individuals to decades in prison based on debunked eugenics theories.”

While the brief in this case focused on the history in Colorado, Loehr’s research is national in scope and he plans to file additional briefs across the country to alert courts to the history behind habitual criminal laws.