Aaron Hernandez committed suicide in prison Wednesday morning, just five days after he was found not guilty of a 2012 double murder in Boston.

The circumstances surrounding Hernandez’s death are suspicious. The former New England Patriots tight end hanged himself from his cell window using a bedsheet, officials said, but that method of suicide is rare in max-security prisons.

Both Hernandez’s agent and lawyer do not believe the ex-Patriot was suicidal, and neither did the Massachusetts Department of Corrections, according to ABC News.

Wrote ABC News: “There were no prior concerns that Hernandez was suicidal, a spokesman for the Massachusetts Department of Correction told ABC News. If there had been concerns, Hernandez would have been on mental health watch in a different part of the prison, the spokesperson said.”

Details of the suicide still are coming to light, but both the Massachusetts State Police and the Worcester Country District Attorney’s Office are launching an investigation into Hernandez’s death. Hernandez’s attorney, Jose Baez, said his firm also will launch its own investigation.

Hernandez had been serving a life sentence without the possibility of parole for the 2013 murder of Odin Lloyd.

Thumbnail photo via The Sun Chronicle/Pool Photo via USA TODAY Sports Images