NEW: Defense attorney says "not one shred of evidence has been presented yet"
NEW: Prosecutor says "there's a tremendous amount of evidence"
Aaron Hernandez pleads not guilty to murder and weapons charges
The former NFL star is also being investigated in 2012 slayings
Former New England Patriots tight end Aaron Hernandez pleaded not guilty Friday in the shooting death of a friend whose body was found in a Massachusetts industrial park.
It was his sixth time appearing in a courtroom since his June 26 arrest.
Hernandez is charged with first-degree murder in the June 17 death of Odin Lloyd, a 27-year-old semipro football player. He also faces various weapons charges. He will be held without bail until his next court appearance on October 9.
Hernandez, 23, was let go by the Patriots after his arrest.
Investigation continues in another case
Friday’s arraignment came as authorities continue to investigate Hernandez in connection with an unsolved 2012 double homicide case in Boston.
Investigators have obtained July 2012 video surveillance allegedly showing Hernandez at a nightclub at the same time as two men who were fatally shot that night, according to a law enforcement source with knowledge of the investigation.
The video apparently does not show Hernandez interacting with Daniel Abreu, 29, and Safiro Furtado, 28, according to a law enforcement source. The development was first reported Wednesday by the Hartford Courant.
Boston police have said the men were inside a BMW that was sprayed with gunfire after they left the nightclub.
Law enforcement sources said they believe Hernandez rented a silver SUV with Rhode Island registration that was linked to the scene of the double homicide.
After Lloyd’s murder, Bristol, Connecticut, police discovered the vehicle by accident while searching the garage of Hernandez’s uncle, a law enforcement source told CNN.
Boston police had been looking for the vehicle for almost a year, law enforcement sources added.
Hernandez has not been charged in the unsolved double shooting.
His attorneys have previously declined to comment to CNN when asked about the ongoing Boston investigation.
Defense: Jury will find him ‘innocent’
A Bristol County, Massachusetts, grand jury last month indicted Hernandez on a first-degree murder charge and five weapons charges.
Prosecutors say Hernandez orchestrated the shooting of Lloyd, who was dating the sister of Hernandez’s fiancee.
Defense attorney Michael Fee said he was pleased with the indictment because it gave his client “a path to trial,” where a jury will find Hernandez “innocent.”
Police have not located the gun believed to have been used to kill Lloyd.
But prosecutors say Hernandez returned a rental car with a bullet casing that allegedly matched bullets found at the scene.
Surveillance cameras showed the car believed to be carrying Hernandez and the others at the southeastern Massachusetts industrial park where Lloyd’s body was found, according to authorities.
Another Hernandez defense attorney, Charles Rankin, asserted that “not one shred of evidence has been presented yet.”
“At the end of the day, we’re confident that Aaron is going to be exonerated and we look forward to that process,” Rankin said.
Bristol County District Attorney Sam Sutter said authorities have more than circumstantial evidence against Hernandez.
“There’s a tremendous amount of evidence,” he told reporters.
One of Lloyd’s sister, Olivia Thibou, said Friday that “these are very difficult days.
“We just keep praying to get through this,” she said.
The next court hearing is scheduled for October 9, when the judge will hear a defense motion to extend and make more stringent a gag order, Sutter said.
Hernandez has been sitting in a jail cell as his former team, known for its stellar offense, contends for another Super Bowl title. The Patriots open their regular season Sunday against the Buffalo Bills.
CNN’s Susan Candiotti, Phil Gast and Michael Martinez contributed to this report.