Fall River, MA (SportsNetwork.com) - The murder trial of former New England Patriots tight end Aaron Hernandez will head to the jury after the prosecution and defense presented closing arguments on Tuesday.

Defense attorney James Sultan told the jury Hernandez didn't commit the June 2013 murder of Odin Lloyd, a semi-pro football player from the Boston area who was dating the sister of Hernandez's fiancee.

Prosecutors say Hernandez and two other men, Ernest Wallace and Carlos Ortiz, drove with Lloyd to a North Attleboro, Massachusetts industrial park, where Lloyd was shot multiple times and left for dead. A jogger found Lloyd's body on June 17, 2013, less than a mile from Hernandez's home.

However, the weapon was never found and prosecutors called more than 130 witnesses in an effort to prove Hernandez pulled the trigger on the handgun that killed Lloyd.

Sultan, during his closing statement, acknowledged for the first time since the start of the trial in late January that Hernandez witnessed the killing. The attorney said the actual crime must have been committed by either Wallace or Ortiz, who will have separate trials on the murder charges.

"He was a 23-year-old kid who witnessed something," said Sultan. "A shocking killing. Committed by someone he knew. He didn't know what to do."

The defense added Tuesday that the prosecution has not yet proven who killed Lloyd, saying police presumed Hernandez's guilt and conducted the investigation around him.

"It's hard to convict someone of murder in our system of justice," Sultan added. "It's supposed to be hard."

Prosecutor William McCauley implored the jury members to pore through the evidence, saying it will lead to a conclusion of Hernandez's guilt on the first-degree murder charge.

"We could ask for nothing more from a jury, but we expect nothing less," McCauley said when asking the jury to return a guilty verdict on the murder charge.

Judge Susan Garsh, in her instructions to the jury, said the panel must conclude beyond a reasonable doubt that the prosecution completely proved Hernandez committed the murder if a guilty verdict is reached.

"Presence alone is not enough to convict the defendant, even if he knew about it," said Garsh, who outlined the requirements for first-degree murder. "The Commonwealth must prove the defendant consciously and purposely decided to kill Odin Lloyd."

"Your verdict must be unanimous," she added.

Hernandez has been incarcerated since his arrest on June 26, 2013. He was released by the Patriots later that day.