Former New England Patriots tight end Aaron Hernandez had a severe case of the brain disease CTE and now a federal lawasuit has been filed against the Patriots and the NFL on behalf of his four-year-old daughter.

Attorney Jose Baez held a press conference in Boston Thursday to make the announcement.

According to the director of the Boston University CTE Center, it has been determined that Hernandez had stage three CTE (out of four stages) and that can cause mood swings, depression and other disorders.

Hernandez killed himself in a prison cell back in April. He was serving a life sentence for murder.

The suit claims the league concealed the dangers of playing football. The NFL has not yet seen the lawsuit and has no comment.

Check out the Baez presser...