The search of Hernandez's sprawling home and vehicle in North Attleboro began in the afternoon and lasted for more than three hours. Locksmiths and several officers were involved, including one with a crowbar.
Detectives and uniformed officers who searched the home, its backyard and playhouse did not comment to reporters on what they were looking for or what caused them to return to the house located not far from where the Patriots practice and about a mile from where a jogger found the body of Odin Lloyd on Monday.
Lloyd family members said Friday that he had been dating the sister of Hernandez's fiancee for about two years. They said the two men were friends who were together the night Lloyd died.
Authorities have ruled Lloyd's death a homicide.
A spokeswoman for the Bristol District Attorney's office declined to comment on the investigation Saturday. A state police spokesman referred questions to the district attorney's office.
An attorney for Hernandez has said he would not comment on the searches.
Three search warrants were issued in the investigation earlier last week but have not been returned, meaning they're not public. No arrest warrants were filed in state courts by the time court closed Friday, Attleboro District Court clerk magistrate Mark E. Sturdy said. Courts were closed Saturday.
Police previously searched in and around the home as they try to figure out who killed Lloyd.
Police in nearby Providence, R.I., said they had assisted Massachusetts state police and North Attleborough police with activity related to the Hernandez investigation at a strip club named Club Desire. It was unclear if they believed Lloyd and Hernandez might have been at the club in the days before Lloyd died.
Patriots spokesman Stacey James has said the team does not anticipate commenting publicly during the police investigation. NFL Commissioner Roger Goodell was waiting for the legal process to take its course.
The Patriots drafted Hernandez out of Florida in 2010. Since then, he has combined with Rob Gronkowski to form one of the top tight end duos in the NFL. He missed 10 games last season with an ankle injury and had shoulder surgery in April but is expected to be ready for training camp. Last summer, the Patriots gave him a five-year contract worth $40 million.