Former Detroit Lions safety Tommy Vaughn was diagnosed with advanced stage 3 chronic traumatic encephalopathy following his death last July, according to the Detroit Free Press' Dave Birkett.
Kristal Vaughn said her father's diagnosis provided some explanation for behavior Birkett described as "more erratic over the years."
"Honestly, as soon as I hung up with the doctor and he gave me the report, I just fell to my knees and started crying even more cause I truly understand my daddy even more,” Kristal said. “And why he’s the way he was."
Kristal recounted how Vaughn would hit members of the family, including her and her mother, and make inappropriate comments, only to often "[have] no recollection of the incidents after they happened."
"I didn’t realize how bad he was," she said. "I thought it was mostly Alzheimer’s and the doc said he did not have Alzheimer’s at all. It was all brain damage."
Vaughn spent seven seasons with the Lions and appeared in 88 games between 1965 and '71.
The physical dangers posed by playing football have been largely self-evident for generations.
The 2013 PBS documentary League of Denial detailed the potential risks of suffering repeated head trauma. The investigation also laid out how the NFL began looking into the matter years before and downplayed the significance of concussions.
In August 2013, the NFL agreed to a settlement with a group of former players who alleged it had failed to disclose the extent to which repeated head trauma could lead to long-term neurological problems.
Earlier this month, the NFL said it would cease using "race-norming" while paying out settlements. The Associated Press' Maryclaire Dale explained how the idea "assumed Black players started out with lower cognitive function."