A man linked to the murder case against former New England Patriots tight end Aaron Hernandez told police Hernandez admitted firing the fatal shots, and a vehicle wanted in a double killing in Boston a year before had been rented in Hernandez's name, according to documents filed Tuesday in Florida that provide the most damning evidence yet against the star athlete.

The documents say Hernandez associate Carlos Ortiz told Massachusetts investigators that another man, Ernest Wallace, said Hernandez admitted shooting semi-pro football player Odin Lloyd in an industrial park near Hernandez's home in North Attleborough. The documents were filed in court by the Miramar, Fla., police department to justify a search of Wallace's home in that city.

The documents also say that while investigating Lloyd's killing, police did searches in Hernandez's hometown, Bristol, Conn., that turned up a vehicle wanted in connection with a July 2012 double homicide in Boston. Police say the vehicle had been rented in Hernandez's name.

Hernandez has pleaded not guilty in Lloyd's killing. His legal team did not return email messages Tuesday.

Prosecutors say Hernandez, Wallace and another man drove with Lloyd to an industrial park where Lloyd was fatally shot.

Ortiz told police that, after picking up Lloyd, the four men headed back to North Attleborough. Along the way, Hernandez told Lloyd that Lloyd had been "chilling" with people Hernandez had problems with, the documents said. But Ortiz told police that the two men shook hands and the problem seemed smoothed over. But soon the car stopped, and everyone but Ortiz got out to urinate, according to Ortiz's account.

The witness also told police he then heard gunshots before Hernandez and Wallace got back into the car without Lloyd and the vehicle sped away.

Wallace faces an accessory to murder charge in the case and has pleaded not guilty.

Meanwhile, eight search warrants were unsealed in Massachusetts after news organizations sought access to the records. The warrants reveal the breadth of the investigation, with authorities scouring through everything from Hernandez's house to his phone to the contents of his team locker, which the Patriots emptied into a container after they released him.

Police seized a rifle and ammunition found in Hernandez's home.

According to the documents, Hernandez became "argumentative" during his first encounter with police at his home following Lloyd's death. He asked, "What's with all the questions?" and locked the door behind him.

He then returned with his attorney's business card but didn't respond when police told him they were investigating a death.

"Mr. Hernandez slammed the door and relocked it behind him," the records read. "Mr. Hernandez did not ask officers whose death was being investigated. Mr. Hernandez's demeanour did not indicate any concern for the death of any person."

Hernandez came out later and agreed to be questioned at a police station, according to the documents.

The documents also say Hernandez called his girlfriend's cellphone and stopped her from speaking with police after they pulled her over and told her Lloyd was dead.