Autopsy: Ex-NFL player who shot 6 shots sustained severe brain trauma.

ROCK HILL (AP) -- An autopsy revealed unusually severe brain disease in a former NFL player. He is accused of shooting six people in Rock Hill before killing himself in April.

Autopsy: Ex-NFL player who shot 6 shots sustained severe brain trauma.

Dr. Ann McKee examined Adams' brain and determined that Phillip Adams, a former football pro, spent twenty years playing football.

According to authorities, Phillip Adams shot and killed Robert Lesslie, a Rock Hill doctor; his wife Barbara; their two grandchildren Adah Lesslie (9 years old) and Noah Lesslie (5 years old); and Robert Shook (38), two HVAC technicians who worked at the Lesslie home. Later, police found Adams with a self inflicted gunshot wound on the head.

CTE, a degenerative disease that is linked to head traumas and concussions, has been shown to cause a variety of symptoms including mood swings and memory impairment.

McKee, who runs the CTE Center at Boston University said that of the 24 NFL players diagnosed with the disease in their 20s or 30s, many had stage 2 like Adams. There are four stages to the disease, with stage 4 being most severe and often associated with dementia.

McKee stated that the second stage is associated to progressive cognitive and behavioral abnormalities like aggression, impulsivity and explosivity as well as paranoia and anxiety.

Adams' CTE diagnosis was unique among the others, as it was "unusually serious" in both his frontal lobes.

In a prepared statement, the Adams family stated that they weren't surprised by the results but were shocked at how serious his condition was.

Their statement stated that they had reviewed his medical records and discovered that he was desperate for help from the NFL. However, he was denied all claims because he couldn't remember simple tasks like driving long distances to see doctors or going through extensive evaluations.

CTE can only be diagnosed by an autopsy. It has been detected in ex-military personnel, football players, boxers, and other people who have suffered repeated head trauma. A recent study revealed signs of the disease in 110 out of 111 NFL players who had their brains examined.

Adams, 32, was a player in 78 NFL games, for six different teams, over six seasons. As a seventh-round pick from South Carolina State, Adams joined the San Francisco 49ers as a draft pick in 2010. He played in 78 NFL games for six teams over six seasons. After retiring, Adams continued his career with Atlanta Falcons in 2015.

Adams was a rookie and suffered a serious ankle injury. He never played again for the 49ers. Later with the Raiders, Adams suffered two concussions in three games in 2012. He didn't retire before 2014 so he would not have been eligible to be tested as part of a large settlement between the league, former players and long-lasting concussion injuries.

After the murders, Adams' sister spoke out to USA Today that Adams' mental health had "degraded fast and horribly" over the past few years. She also stated that the family was seeing "extremely concerning" signs and symptoms of mental illness such as an increase in temper and neglecting personal hygiene.