The revelation that N.F.L. star Aaron Hernandez had degenerative brain disease raises questions about the athlete’s culpability in the death of his friend, Odin Lloyd, Professor Lisa Tucker wrote in an op-ed published in the New York Times on Sept. 24.

The op-ed, co-written with University of Baltimore School of Law Professor J. Amy Dillard, explored the legal ramifications of a recent discovery that Hernandez had a severe form of chronic traumatic encephalopathy, or C.T.E. The results of Hernandez’s posthumous brain scan recently became public, several months after the former New England Patriot hanged himself in a prison cell at age 27.

Tucker and Dillard note that a study published in the Journal of the American Medical Association in July revealed that 110 of 111 brains of deceased NFL players donated by their families showed signs of C.T.E.

Citing the disproportionate number of football players who are charged with violent crimes, the co-authors contend that C.T.E. deprives players of the capacity to handle disputes rationally and may represent a form of insanity.

“Under the Massachusetts formulation of the insanity defense, if he were tried today, Mr. Hernandez might successfully assert that, when he killed Mr. Lloyd, he suffered a mental defect that rendered him substantially unable to conform his conduct to the requirements of the law, utterly unable to make himself behave as the law requires,” the co-authors wrote. “Could the evidence of C.T.E. now create a reasonable doubt about his criminal responsibility? Almost certainly.”

Tucker and Dillard went on to argue that the legal community should consider viewing pro football players “who have spent years treating their heads like battering rams” as incapacitated individuals with significantly impaired impulse control.

“Aaron Hernandez should be sitting in a therapeutic hospital receiving care for a profound brain injury,” they concluded. “Instead, his ashes sit with his family. Suicide appears to be another result of C.T.E.”