O.J. Simpson's erratic behavior over the years has painted the former football star as a dangerous person -- maybe even a monster. But as the effects of CTE become more understood in the medical community, Simpson is starting to be seen as someone who may be afflicted by the disease himself.
Dr. Bennet Omalu, the groundbreaking physician who discovered CTE, and who was recently portrayed in the movie "Concussion" by Will Smith, is all but convinced.
"I would bet my medical license that he has CTE," says Omalu to PEOPLE Magazine. He adds: "Given his profile, I think it's not an irresponsible conclusion to suspect he has CTE."
CTE cannot be formally diagnosed in a living person -- a study of the brain post-death is the only way to confirm a case. But CTE has become associated with a variety of symptoms evident in life, including mood swings, violence, emotional reactions to mundane stresses, and even criminal behavior.
CTE in NFL vets
Mike Webster #52
As a player, Mike Webster was an all-time great, earning nine Pro Bowl selections and winning four Super Bowls with the Steelers. In 1997, Webster was inducted into the Pro Football Hall of Fame.
Mike Webster #52
Unfortunately, Webster's post-football life was troubled. He was afflicted by amnesia, depression and dementia in his later years, many of which he spent homeless despite having relatives willing to house him. After his death in 2002, he became the first NFL veteran diagnosed with CTE.
Forrest Blue #75
As an offensive lineman, Forrest Blue was a four-time All-Pro. His eleven-year NFL career was split between the San Francisco 49ers and Baltimore Colts. Blue died in 2011 in an assisted care facility, after which he was diagnosed with CTE.
Lew Carpenter #30
Lew Carpenter made a 47-year career out of football. After playing at the University of Arkansas the running back spent 10 years playing for the Cleveland Browns, Green Bay Packers and Detroit Lions. He retired from coaching in 1996 due to health reasons and died in 2010, agreeing to donate his brain to science.
Lou Creekmur #76
An eight-time Pro Bowl offensive lineman, Lou Creekmur suffered from a 30-year decline in mental health leading up to his death in 2009. He was 82.
Shane Dronett #99
After a 10-year career in the NFL, defensive lineman Shane Dronett experienced significant cognitive troubles in 2006. He suffered from confusion, paranoia, and bouts of rage. In 2009, he picked up a gun and confronted his wife, who fled. In her absence, Dronett fatally shot himself. He was 38.
Dave Duerson #26
In 11 NFL seasons, Duerson was a four-time Pro-Bowler and the 1987 NFL man of the year. In 2011, he shot himself in the chest and died. Duerson had suspected something regarding his mental health: just before shooting himself, he texted his family asking them to donate his brain to science.
Ray Easterling #32
An eight-year veteran who spent his entire career with the Atlanta Falcons, Ray Easterling was one of the veterans to add his name to a federal lawsuit against the NFL regarding concussions. In April 2012, he fatally shot himself, allegedly due to the worsening of his clinical depression and the deterioration of his cognitive functioning.
Cookie Gilchrist #2
Between the CFL and the AFL, Cookie Gilchrist earned nine All-Star bids. The running back was also a two-time AFL rushing champion. After his playing career, Gilchrist displayed erratic and sometimes angry behavior, particularly to those he had worked with in his playing days. He died in 2011 and was diagnosed with advanced CTE.
John Grimsley #59
A 10-year NFL veteran, Grimsley is best known for making the Pro Bowl in 1988. In 2008, he died of an apparent accidental gunshot wound, after which he was diagnosed with CTE.
Chris Henry #15
Henry's CTE diagnosis was a breakthrough that brightened the spotlight on football's dangers. After several run-ins with the law, Henry died in 2009 from a motor vehicle accident. An autopsy revealed that Henry had CTE at just 26 years old. He was the first still-active NFL player to be diagnosed with the condition.T
Terry Long #74
Long was a consistent starter for the Steelers from 1984 until his retirement in 1991. That same year, Long tested positive for steroids and attempted suicide. He eventually killed himself in 2005 by drinking antifreeze.
John Mackey #88
A five-time Pro Bowler and two-time NFL champion, John Mackey was only the second tight end ever admitted to the Pro Football Hall of Fame. After his playing days, Mackey was afflicted with dementia, and his condition worsened until he required full-time care in an assisted living facility. He died in 2011.
John Mackey #88
Since John's death, his wife, Sylvia Mackey, has become a powerful advocate for NFL veterans and continues to push the NFL to change through her activism and legal work.
Ollie Matson #33
In addition to having a 14-year NFL career, Ollie Matson also won two medals at the 1952 Olympics. He died in 2011 from complications from dementia and was later diagnosed with CTE.
Tom McHale #73
A bruising defensive end with an Ivy League education, Tom McHale played in the NFL from 1987 to 1995. He died in 2008 from an accidental drug overdose. His widow now works for the Boston University CTE Center as a family relations liason.
Junior Seau #55
Perhaps the most accomplished player to be diagnosed with CTE, Junior Seau was a 12-time Pro Bowler, the 1994 AFC Player of the Year, and a member of the NFL 1990s All-Decade team.
Junior Seau #55
In May 2012, Seau was found dead from a self-inflicted gunshot wound to the chest. While never diagnosed with a concussion during his playing career, Seau's wife reported that he did admit to experiencing several. The linebacker also experienced insomnia for years leading up to his death.
Justin Strzelczyk #73
As an offensive lineman for the Pittsburgh Steelers, Strzelczyk's career was cut short by his erratic off-field behavior and legal troubles. Upon his death in a high-speed police chase in 2004, alcohol and drugs were initially blamed. An autopsy revealed that the lineman had suffered brain damage.
Andre Waters #20
During his 12-year NFL career, Andre Waters earned a reputation as one of the hardest hitters in the NFL. Unfortunately, Waters wound up shooting himself in the head in 2006. An autopsy discovered brain damage sustained during his playing days.
Jovan Belcher #59
A young, promising NFL linebacker, Jovan Belcher killed himself in a murder-suicide in December 2012. After killing his girlfriend, Belcher drove to the Kansas City Chiefs' practice facility and shot himself with a handgun in the parking lot.
Jovan Belcher #59
After Belcher's death, an autopsy diagnosed CTE in the 25-year-old.
Simpson may be aware of some of those changes. In a sworn statement given during a 2008 trial for armed robbery, Simpson tried to portray himself as someone whose judgment had been impaired by years of head trauma playing football.
"I was knocked out of games for such head blows repeatedly in the 1970s and other times I continued playing despite hard blows to my head during football games," he said, according to PEOPLE.
PEOPLE also reports that friends and associates close to him have observed dramatic changes in his behavior, and now see him as an unstable individual with unexplained mental problems.
The former Heisman Trophy winner is up for parole in 2017. But if he does suffer from CTE, it's unlikely his behavior will change for the better.
In 2014, HBO's Real Sports did a story about the connection between concussions and domestic violence. Here is part of the report:
