Investigators were searching the North Attleboro, Mass., home of New England Patriots tight end Aaron Hernandez following the killing of a man police call an "associate" of player No. 81, ABC News has learned.Hernandez jersey number is 81.Two Hernandez friends tried to leave house at the time of the search, but they were stopped by a state police car at the end of driveway.Massachusetts investigators also planned to interview Hernandez in connection with the killing, ABC News has learned.New England Patriots tight end Aaron Hernandez looks on during an NFL football game against the Jacksonville Jaguars at EverBank Field, Dec. 23, 2012, in Jacksonville, Fla.Hernandez has been uncooperative with police since the body of a 27yearold man was found in an industrial park not far from the Patriots player home, two law enforcement sources said.A rental vehicle with Rhode Island plates was recovered near the scene, which led investigators to Hernandez, sources told ABC News.Stacey