FILE - In this Monday, Dec. 23, 2013, file photo, former New England Patriots NFL football player Aaron Hernandez is led into his court appearance at the Fall River Superior Court in Fall River, Mass. Massachusetts prison officials said Hernandez hanged himself in his cell and was pronounced dead at a hospital early Wednesday, April 19, 2017. (Matt Stone/The Boston Herald via AP, Pool, File)
FILE - In this Monday, Dec. 23, 2013, file photo, former New England Patriots NFL football player Aaron Hernandez is led into his court appearance at the Fall River Superior Court in Fall River, Mass. Massachusetts prison officials said Hernandez hanged himself in his cell and was pronounced dead at a hospital early Wednesday, April 19, 2017. (Matt Stone/The Boston Herald via AP, Pool, File) Credit: Matt Stone

Boston — Massachusetts state police say they have launched an investigation into Aaron Hernandez’s death by hanging in prison.

Worcester District Attorney Joseph Early, Jr., said detectives assigned to his office and the Department of Correction are investigating the death of Hernandez, who was serving a life sentence for the 2013 murder of Odin Lloyd.

Hernandez was acquitted on Friday of a 2012 double homicide in Boston.

Authorities say Hernandez, a former NFL star for the New England Patriots, used a bedsheet to hang himself early this morning at the Souza-Baranowski Correctional Center in Shirley, Mass.

Early says Massachusetts’ chief medical examiner is conducting an autopsy in Boston to determine the exact cause and manner of death.

Bristol County District Attorney Thomas Quinn prosecuted Hernandez in the 2013 murder of Lloyd. Quinn calls Hernandez’s death “a shocking and sad end to a very tragic series of events that has negatively impacted a number of families.”