The details of the information are not revealed in the court filing, but it is the first clue to what prosecutors may point to as the motive in the June 17 slaying of Odin Lloyd of Franklin, Mass., the Hartford Courant reported Saturday.
Hernandez, a former New England Patriot tight end, is charged with killing Lloyd, who was dating the sister of Hernandez's fiancee. Hernandez has been held without bail since his arrest at his North Attleboro, Mass., home in late June.
He became a suspect in the 2012 drive-by shooting deaths in Boston homicides after authorities received a tip that they were related to the Lloyd killing.
Prosecutors contend the two men had a disagreement at a nightclub that led Hernandez to shoot Lloyd.
Hernandez appeared in court Friday for a hearing. Lloyd's possible knowledge of the double homicide was not discussed, but Bristol County Assistant District Attorney William McCauley said in a letter to Hernandez's lawyers he had turned over to them evidence that Lloyd possessed information about the double homicide, the Courant reported.
Defense lawyers disclosed that a man named Robby Olivares was with Hernandez and Lloyd the night Lloyd was killed.
Olivares described himself as Hernandez's barber during grand jury testimony, and said he was at the former football player's house the day before his arrest.
Olivares may become a key witness in the case, the Courant reported.