The body of 27-year-old Odin Lloyd was found June 17 in an industrial park a mile from Hernandez's North Attleborough home. Police arrested Hernandez on Wednesday and charged him with orchestrating the execution-style shooting.
Shortly after news of Hernandez's arrest, the Patriots announced that they released him. The 2011 Pro Bowl selection had signed a five-year contract last summer with the Patriots worth $40 million.
Members of Lloyd's football team chanted his name as pallbearers placed his casket in a hearse outside Church of the Holy Spirit in Boston's Mattapan neighborhood.
Prosecutors allege Hernandez arranged the killing because Lloyd talked to the wrong people at a nightclub.
Lloyd had known Hernandez for about a year and was dating the sister of Hernandez's fiancee, the mother of Hernandez's 8-month-old baby, according to Hernandez's attorney, Michael Fee.
Hernandez has pleaded not guilty and is being held without bail. A judge denied his bail appeal Thursday after a prosecutor revealed that a Hummer belonging to Hernandez turned up an ammunition clip matching the caliber of casings found at the scene of Lloyd's killing. The 23-year-old was also charged with five other gun-related charges. He could face life in prison if convicted.
Two other men are also in custody. Prosecutors say the three were with Lloyd shortly before his death.
Investigators are also looking into a link between Hernandez and a 2012 double homicide, law enforcement officials told ABC News.
The July 15, 2012 incident involves a drive-by shooting in Boston's South End. Three people were shot, and two of them were pronounced dead at the scene.
The Associated Press and ABC News contributed to this report.