A look back on the talented player’s NFL start and the series of events that ultimately resulted in his death.

An attorney for former New England Patriots tight end Aaron Hernandez announced Thursday a $20 million lawsuit had been filed in federal court against the New England Patriots and the NFL on behalf of the ex-player’s former fiancée, Shayanna Jenkins Hernandez, and the couple’s daughter.

The lawsuit was filed the same afternoon as it was announced that Hernandez had been diagnosed with chronic traumatic encephalopathy (CTE).

The 18-page filing, a copy of which was obtained by USA TODAY Sports, contends both the league and team “were fully aware of the damage that could be inflicted from repetitive impact injuries and failed to disclose, treat or protect him from the dangers of such damage.”

More: Aaron Hernandez had CTE and that’s a huge problem for NFL

The Boston University CTE Center said in a news release that an examination of Hernandez’s brain showed signs of an advanced form of the disease. CTE, which can only be diagnosed in an autopsy, can be caused by repeated head trauma and leads to symptoms like violent mood swings, depression and other cognitive difficulties.

While serving a sentence of life sentence for the murder of former semi-pro football player Odin Lloyd, Hernandez was found hanged in his jail cell at the Souza Baranowski Correctional Center in Shirley, Mass., in April. His death at age 27 was ruled a suicide. 

“As a result of the defendants’ conduct and the injury experienced by Aaron, Avielle Hernandez was deprived of the love, affect, society and companionship of her father while he was alive,” states the lawsuit filed in U.S. District Court in Boston.

The Patriots did not immediately return a message left by USA TODAY Sports. NFL spokesperson Brian McCarthy said in an email the league had not seen the lawsuit and declined comment.  

“Not only were the results positive, but we’re told it was most severe case (BU) had ever seen for someone of Aaron’s age,” said Jose Baez, who represented Hernandez at his second murder trial, at a news conference on Thursday. “Aaron Hernandez had an advanced stage 3 of…