Ernest Wallace, of Miramar, Fla., pleaded not guilty Monday in Attleboro, Mass., court. He mouthed "I love you" to some people sitting in the courtroom. He returns to court July 22.
Odin Lloyd was found slain June 17 at an industrial park in North Attleborough not far from Hernandez's home.
Prosecutors say Wallace and another man, Carlos Ortiz, were with Hernandez when they drove with Lloyd to the industrial park. They have not said who shot him. Prosecutors say Hernandez orchestrated the killing because he was upset at Lloyd for talking to certain people at a nightclub a few days earlier.
Hernandez has pleaded not guilty.
Meanwhile, Attleboro District Court Judge Daniel O'Shea on Monday said he will release impounded search warrant materials in the murder case at 2 p.m. ET on Tuesday.
Motions to unseal the material were filed by The Patriot Ledger and Taunton Gazette newspapers and their parent Gatehouse Media, supported by The Associated Press, and by The Boston Globe.
Prosecutors and Hernandez's defense attorney had opposed releasing the material. District Attorney Samuel Sutter said Monday he would not appeal the judge's decision.
Information from The Associated Press was used in this report.