The death of former New England Patriots tight end Aaron Hernandez was ruled a suicide, the Worcester County District Attorney’s Office announced on Thursday.

Hernandez was found hanged by a bed sheet inside his cell at the Souza Baranowski Correctional Center in Shirley, Mass., early Wednesday morning and was pronounced dead the hospital about an hour later.

The Massachusetts chief medical examiner, Dr. Henry N. Nields, concluded the “manner of death was suicide and the cause asphyxia by hanging,” according a news release.

“There were no signs of a struggle, and investigators determined that Mr. Hernandez was alone at the time of the hanging,” the district attorney’s office said in the statement.

Investigators from the Massachusetts State Police found three handwritten notes in the cell located next to a bible. The content of those notes were not immediately released.

Hernandez, 27, was locked in his cell in the general population area of the maximum-security prison at 8 p.m. ET Tuesday and investigators determined nobody entered the cell until correction officers forced their way in at 3:03 a.m. on Thursday. Hernandez had “impeded” easy entry into the cell, according to the statement.

PHOTOS | Aaron Hernandez