Belcher, 25, shot and killed his girlfriend on the morning of Dec. 1, 2012, before killing himself hours later. The doctor who examined Belcher's brain, Piotr Kozlowski, wrote in a report obtained by ESPN's "Outside the Lines" that he identified tangles of a protein connected to CTE, which has been identified in multiple deceased NFL players.
Researchers say that CTE -- a degenerative brain disease linked to memory, aggression and depression, among other symptoms -- is caused by repeated head trauma. Multiple former players have been diagnosed posthumously with the disease. Among the former players found to have CTE is former Chargers linebacker Junior Seau, who committed suicide in May 2013.
Lawyers representing Belcher's daughter reportedly requested the analysis on Belcher's brain. They have filed a wrongful death lawsuit against the Chiefs. Belcher's mother filed a separate wrongful death suit against the team.
From the OTL report:
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."
Earlier this month, the NFL and lawyers of retired players released actuarial reports behind the $765 million concussion settlement that was granted preliminary approval earlier this summer. Belcher's daughter and mother could be compensated under the terms of the settlement.