aaron hernandez
Former New England Patriots tight end Aaron Hernandez and his attorney Charles Rankin listen to testimony during Hernandez' murder trial at Bristol County Superior Court in Fall River, Massachusetts, February 4, 2015. Reuters

After more than a year and a half, the Aaron Hernandez murder trial is finally underway. The former star tight end of the New England Patriots is facing life in prison for allegedly shooting and killing Odin Lloyd, a semi-pro football player, on the early morning of June 17, 2013.

Inclement weather delayed the trial for three days, but the jury has already heard testimony from multiple witnesses, in addition to opening statements from the prosecution and the defense. Potentially damning evidence has been presented to the court, but the key piece of evidence is still nowhere to be found.

Hernandez has pleaded not guilty to first-degree murder, but he isn’t the only person facing jail time for Lloyd’s death. Ernest Wallace and Carlos Ortiz, Hernandez’s alleged accomplices, have been indicted on murder charges, as well. Hernandez’s fiancée has been charged with perjury.

Below are six important things to know about the trial.

Juror Dismissed

Less than a week into the trial, one of the jurors has been dismissed. Judge Susan E. Garsh dismissed a female juror, following a private hearing that was held on Tuesday. According to Garsh, the woman lied about not having a previous opinion on the case.

“Over the last few years, the juror has expressed an interest in serving on this particular jury,” Garsh said, in a measured tone. “Discharge of the juror is indeed in the best interest of justice.”

The juror also lied about going to Patriots’ games on a questionnaire. She was part of an 18-person panel, in which six jurors would become alternates, before the start of deliberations.

Shaneah Jenkins' Testimony

Lloyd's girlfriend took the stand on Tuesday, giving her account of what happened after her boyfriend was murdered. Jenkins was not a witness to any wrongdoing, but her testimony provides circumstantial evidence that could lead the jury to believe Hernandez killed Lloyd, and Shayanna Jenkins, Shaneah’s sister and Hernandez’s fiancée, helped cover up the crime.

According to Shaneah Jenkins, she called Hernandez on the morning of Lloyd’s death, as well as later on in the day, but the former NFL player never got back to her. Shaneah sat with her sister in Hernandez’s home, a few hours after Lloyd’s body was found. She says Shayanna received multiple phone calls and responded with one word answers, acting "secretive" and "not normal."

At one point, Shayanna allegedly ventured into the basement with a black plastic bag. Moments later, Shaneah saw her sister walking from the backyard towards the house, eventually asking Shaneah if she could borrow her car to go to the bank. Shayanna was gone for 30 minutes, during which time the prosecution suggests she disposed of the murder weapon. Home video shows her leaving with something “rigid” in the black bag, and returning without the “rigid” item.

No Murder Weapon

The prosecution has its share of evidence, but police never found the murder weapon that they believe Shayanna Jenkins disposed of, in order to protect Hernandez. Authorities have long been looking for the gun that was used to kill Lloyd, searching Hernandez’s multiple residences, his cars, his uncle’s house, and the area in which Lloyd’s dead body was found.

Five .45 caliber rounds were recovered from Lloyd’s body, and it was discovered in the autopsy that two more rounds went through his body. At a June 16 hearing, Bristol County District Attorney William McCauley said two witnesses told a grand jury that Hernandez kept a .45 caliber gun in a black metal box in his basement.

Text Messages

A month before the trial began, the judge ruled that text messages Lloyd sent shortly before his death could not be shown to the jury. The prosecution said the messages showed that Lloyd could sense that Hernandez was going to murder him.

“U saw who I was with ... NFL ... Just so U know,” Lloyd texted his sister, before he died.

Text messages sent from Hernandez the day after the murder, however, have been presented in court. The prosecution has suggested that one text sent from Hernandez to his fiancée is instructing her to get rid of the murder weapon.

"Go back in back of the screen in movie room when u get home an there is a box…jus in case u were looking for it!!! Member how you ruined the big tv lmao WAS JUST THINKIN bout that lol wink wink love u TTYL….K,” read the message sent on June 18.

Circumstantial Evidence

Not having the murder weapon will make it more difficult for the prosecution to convict Hernandez. However, there is a lot of circumstantial evidence that might convince the jury that Hernandez is guilty.

There is no video of Hernandez shooting Lloyd, but video evidence shows the former New England Patriot driving with Lloyd on the night of the murder. Video also shows Hernandez driving with two other people, in addition to Lloyd, towards where Lloyd’s body was found, but returning with just two passengers, allegedly Wallace and Ortiz.

Surveillance footage shows Hernandez holding something in his house, which prosecutors claim is a gun, shortly after Lloyd was killed.

DNA evidence also links Hernandez to the scene of the crime. His DNA was found on a joint that was next to Lloyd’s body, and his DNA was discovered on a bullet casing in the car that he drove on the night of Lloyd’s death.

Motive

Lloyd’s death isn’t the only murder for which Hernandez is being charged. In a separate case, he is being charged with a July 2012 double homicide in Boston, allegedly shooting two men in a car as they waited at a red light.

It’s been suggested that the murders might be connected to Lloyd’s death, because Hernandez thought the semi-pro football player knew too much about the incident. The judge, though, has ruled that the prosecution cannot talk about the other case in front of the jury.

According to the defense, Hernandez had no reason to murder Lloyd, as the two were "partying pals." Hernandez was "planning his future, not a murder," said defense attorney Michael Fee.

Just 10 months before Lloyd’s death, the former NFL tight end signed a five-year contract extension that was valued up to $40 million.

Fee told the jury that the authorities have not done their job the correct way.

“The investigation was sloppy and unprofessional. What about the facts that showed Aaron’s innocence?” Fee said on Day 1 of the trial. “The evidence will show that they were ignored.”