JOE CAVARETTA/Associated Press

Former NFL running back Lawrence Phillips, who was found dead of an apparent suicide at the age of 40 at Kern Valley State Prison in Delano, California, on Wednesday, will have his brain studied by chronic traumatic encephalopathy (CTE) researchers.

According to Josh Peter and A.J. Perez of USA Today, Dan Chamberlain, the family's attorney, said Phillips' mother, Juanita Phillips, "has agreed to donate her son's brain to Boston University's Center for the Study of Traumatic Encephalopathy."

In September 2015, PBS' Frontline noted a Department of Veterans Affairs and Boston University study found that 87 of 91 former NFL players studied tested positive for CTE.

Chamberlain told USA Today why Phillips' mother opted to release her son's brain to the university.

"She wanted an explanation about what happened, and I told her, 'Look, the only way you can really explain it is by examining his brain,'" Chamberlain said. "I told her, 'You owe it to your son, you owe it to every other NFL, college and Pee Wee and high school and middle school player that played football.'"

Chamberlain added that Phillips' estate could receive up to $5 million from the NFL's concussion settlement with players.

Phillips was a star in college at the University of Nebraska, winning back-to-back national titles in 1994 and 1995, but various problems off the field hindered his career. He played three seasons between 1996 and 1999 in the NFL with the St. Louis Rams, Miami Dolphins and San Francisco 49ers.