A medical report, obtained by "Outside the Lines," shows that the brain of former Chiefs LB Jovan Belcher -- who fatally shot his girlfriend before killing himself -- had signs consistent with CTE, a brain disease triggered by repeated head trauma. (2:24)

The brain of former Kansas City Chiefs linebacker Jovan Belcher -- the 25-year-old player who shot and killed his girlfriend in 2012 before committing suicide -- showed signs of pervasive brain damage like that found in other deceased NFL players, according to a neuropathologist.

In a report obtained by "Outside the Lines," Dr. Piotr Kozlowski writes that he detected neurofibrillary tangles of tau protein, which is identified with chronic traumatic encephalopathy. The tangles were distributed throughout Belcher's hippocampus, an area of the brain involved with memory, learning and emotion.

Jovan Belcher fatally shot his girlfriend, Kasandra Perkins, multiple times before killing himself at Arrowhead Stadium on Dec. 1, 2012. Jeff Curry/USA TODAY Sports

Dozens of former NFL players have been diagnosed posthumously with CTE, a neurodegenerative disease linked to dementia, memory loss and depression. The disease, researchers say, is triggered by repeated head trauma.

On Dec. 1, 2012, Belcher shot and killed girlfriend Kasandra Perkins, the mother of his then-3-month-old daughter. Belcher then drove to the Chiefs' practice facility, where he shot himself in front of team officials in the parking lot. While the murder-suicide reignited the debate over athletes and guns, it also increased the focus on a frequently overlooked issue at the time: the NFL's domestic violence problem.

Belcher's body was exhumed one year after his death, and his brain was examined two weeks later. Kozlowski was hired to diagnose the brain by court-appointed Kansas City attorneys who represent the interests of Belcher's daughter. Belcher's mother, Cheryl Shepherd, initiated the process of exhuming her son's body to have his brain studied, attorney Dirk Vandever said.

Vandever declined to comment about why his law firm released Kozlowski's findings now, almost nine months after the diagnosis. "Outside the Lines" requested copies of images of Belcher's brain to send to another neuropathologist for independent analysis, but that request was denied.

Neurosurgeon Dr. Julian Bailes, chairman of the department of neurosurgery and co-director of the NorthShore Neurological Institute in Chicago, did not study Belcher's brain but said of the possible findings: "It is of great interest. Violence against others is not typically part of the CTE picture. But it was in the case of [former professional] wrestler Chris Benoit. It would be nice to have these findings corroborated.

"If correct, they're very compelling."

If it can be shown that Belcher did have CTE, Belcher's daughter and mother, together, would be eligible for up to $4 million under the proposed concussion settlement between the NFL and former players. Furthermore, the lawyers representing Belcher's daughter have filed a wrongful-death lawsuit against the Chiefs on her behalf. Belcher's mother, with different attorneys, filed an almost identical suit.

Among the allegations contained in the lawsuits is that Belcher was knocked unconscious during a game against the Jacksonville Jaguars in 2009 and did not receive adequate treatment. The lawsuits also refer to a November 2012 game against the Cincinnati Bengals when, the lawsuits allege, Belcher "suffered what should have been recognized as an acute concussion." However, one lawsuit continues, "despite exhibiting obvious symptoms, Decedent was never removed from play for evaluation and recovery." The lawsuits also claim Belcher exhibited signs of CTE, including changes in his mood and behavior.

"The NFL has a long history of a changing the rules of the game to make it safer on the field, providing players the best medical care, and updating protocols on diagnosing concussions, treating concussions, and returning to play after a concussion," the league said in a statement.

The NFL said it has funded $161 million in CTE and related research projects, including a $30 million grant to the National Institutes of Health in 2012.

The Chiefs declined to comment.

Kozlowski, through Vandever, was not made available for comment. According to the American Board of Pathology, he is certified in anatomic pathology and neuropathology. He was formerly a program director at the National Institutes of Health Institute for Neurological Disorders and Stroke in Maryland. Kozlowski serves as the dean of research and pathology professor at the Touro College of Osteopathic Medicine in New York City.

Vandever said Belcher's mother had the idea of having her son's brain studied after reading multiple reports about football players and CTE. He declined to discuss why Kozlowski was chosen as opposed to researchers who are more experienced in the study of CTE and football players -- those from Boston University and the NIH, for example.

As for Belcher's brain being examined slightly more than a year after his death, Kozlowski's report refers to some brain decomposition, with certain parts better preserved than others. Bailes said it is possible to find evidence of tau protein and CTE-like changes a year after a death.

Bailes, who has studied the connection between football players and head injuries, worked on the case of Andre Waters, a former Philadelphia Eagles safety who committed suicide by shooting himself in the head. "Even in this case of a gunshot wound to his brain, it was possible to diagnose him with CTE," Bailes said of Waters.

Steve Delsohn is a reporter in ESPN's Enterprise/Investigative Unit and can be reached at stevedelsohn@aol.com.