Taking center stage this week -- videotape never before seen in public, taken from Hernandez's own home security system.
Prosecutors are using that grainy footage to suggest Hernandez is holding a .45-caliber handgun -- the same kind police say was used to kill Lloyd. Hernandez is seen on camera pulling into his driveway minutes after Lloyd was shot to death in an industrial park about a mile from Hernandez' Boston home.
Hernandez, Ernest Wallace, and Carlos Ortiz are seen on the same security video, recorded at about 3:30 a.m. on June 17, 2013, after the men walk into Hernandez's home. All three have been charged with murder in the death of Lloyd and have pleaded not guilty. Wallace and Ortiz are being tried separately.
The video is time-stamped minutes after workers in a nearby industrial park describe hearing loud noises like fireworks -- the moment prosecutors say Lloyd was gunned down after getting out of a car driven by Hernandez.
Jurors lean forward in their chairs, peering into monitors and scribbling notes as Aspinwall, a former Massachusetts state trooper and New Hampshire police chief, takes them frame by frame through video during two days of testimony.
Aspinwall tells jurors Hernandez appears to be holding the pistol by its muzzle as he's standing at his basement door.
The defense will have none of it. They attack Aspinwall's credentials. Aspinwall is well-schooled in Glocks but admits he doesn't consider himself a gun identification expert.
Hernandez's lawyers then show a different part of the video time-stamped a few seconds earlier with Hernandez holding what appears to be a shiny object in one hand, suggesting it may be an iPad.
"Glock pistols don't have white glows to them, do they?" defense attorney James Sultan asks.
"No, they do not," Aspinwall answers.
Sultan then displays a soft-pellet gun similar in shape to a Glock, suggesting it could also be the object Hernandez is holding.
Prosecutors dispute the suggestion.
"Are you aware of anybody going pellet gun shooting at 3:30 in the morning?" Bristol County Assistant District Attorney Patrick Bomberg asks Aspinwall.
University of New Hampshire law professor Michael McCann calls the Glock expert's findings powerful; yet, he thinks the defense did a solid job of raising questions about the fuzzy video.
"The jury might think that the defense is just throwing things against the wall," he says. "But on the other hand, the jury may feel like it could be one of a dozen things. That's reasonable doubt."
One thing not in dispute: the alleged murder weapon remains missing.
So does a solid motive.
What's the motive?
Prosecutors could be laying the groundwork for showing more surveillance video of Hernandez -- who at the time was a star receiver for the New England Patriots -- partying with Lloyd and Hernandez's personal barber at Rumor nightclub two nights before Lloyd's death.
Investigators say Hernandez was angry that Lloyd was talking to some people that night.
Hernandez and Lloyd are not seen together on a camera pointed at the club's bar, and they appear to be separated for a time when they leave, but so far there's no testimony about what may have gone wrong.
Akil Joseph, a longtime friend of Lloyd's who takes the stand, tells jurors he talked with Lloyd at the club and says he appeared "normal." When Azil Joseph leaves the stand, he keeps his eyes locked on Hernandez until he walks past the defense table.
What did the valet see?
Cameras show Hernandez leaving the bar, but they do not show the moment when a parking valet testified he saw what he believed to be a gun in Hernandez's waistband. The valet's hotel security boss tells jurors he didn't see a weapon under the football player's shirt.
Near the club, Hernandez is in his SUV with Lloyd and another friend. Hernandez offers a ride to Jennifer Fortier, his babysitter, who happened to be nearby with a friend.
Fortier tells jurors Hernandez and Lloyd were smoking pot. Despite her objections, Hernandez drives her and the friend to Hernandez's so-called "flophouse" about 20 minutes from Gillette Stadium, the Patriots' home field in Foxborough.
Fortier testifies that Hernandez "tried kissing me."
"I told him 'No, I'm your nanny. I can't do this,'" she adds. "He said he understood ... and he wasn't mad at me."