(CNN) -- It was around 2:30 a.m. on June 17 when Odin Lloyd climbed into a silver Nissan Altima.
He had company.
Hours later, Lloyd was dead, shot with a .45-caliber firearm and later found lying in a gravel pit in the southeastern Massachusetts town of North Attleborough.
As of Friday afternoon, the three others who had been in the car with Lloyd were in custody, authorities said.
"We believe we have the three individuals ... and we're very pleased about that," Bristol County, Massachusetts, District Attorney Sam Sutter said.
Foremost among the suspects is Aaron Hernandez. He'd been a star tight end with the New England Patriots, at least until the team released him shortly after his arrest Wednesday.
The Bristol, Connecticut, native pleaded not guilty this week to a premeditated murder charge, among others.
"It is a circumstantial case. It is not a strong case," his attorney, Michael Fee, said this week in court.
The cloud over Hernandez doesn't end there. A law enforcement source told CNN that Boston police are "very active" -- and making progress -- in trying to connect the dots that could link Hernandez to an unsolved drive-by shooting that left two people dead last summer in Boston's South End.
In a related development, a silver sport utility vehicle owned by Hernandez that police believe is linked to that double homicide was impounded in Bristol, a law enforcement source told CNN.
The Boston Globe reports that the unsolved shooting deaths of two men might have played a role in the motive for Lloyd's death. The newspaper quoted two law enforcement officials as saying Lloyd may have had information linking Hernandez to the shooting.
"The motive might have been that the victim knew (Hernandez) might have been involved," the paper said, quoting one of the officials, who asked for anonymity due to the sensitive nature of the investigation.
For now, prosecutors contend that something Lloyd may have done or said didn't sit well with the NFL standout. Two days later, they allege, Hernandez rounded up some friends and orchestrated the hit, to settle the score.
On Wednesday, the same day authorities showed up at Hernandez's door and took him away in a police car, 27-year-old Carlos Ortiz was similarly arrested in Bristol and charged as a fugitive from justice.
Ortiz was in a Massachusetts court Friday. According to his attorney, John Connors, Ortiz pleaded not guilty to a single charge of carrying a firearm without a license. The charge was related to an incident that allegedly took place in Massachusetts, though it was not immediately known if it had any connection with Lloyd's killing or the double homicide in 2012.
He'll remain behind bars until a July 9 hearing at which time Connors said he plans to press a judge to set bail.
"Mr. Ortiz struck me as being a gentle person who is confused as to how he is in this situation," Connors said following his first, brief meeting with his client Friday afternoon. "... We're going to try and prove he's not guilty."
Meanwhile, Ernest Wallace turned himself in Friday in Miramar, Florida, nearly 1,500 miles away. Police there said Wallace had seen news reports of an arrest warrant being issued for him out of North Attleborough.
Wallace appeared before a judge in Broward County, Florida, on Saturday, and is charged with accessory after the fact of murder.
Lloyd's last few hours
Prosecutors have alleged Lloyd's killing had something to do with a run-in between him and Hernandez over the weekend.
The two met up at the popular Boston dance club, Rumor, according to Lloyd's sister, Olivia Thibou.
Then, in the predawn hours of June 17, Hernandez swung by in the rented Altima to pick up Lloyd -- a semipro football player who also worked as a landscaper and was dating the sister of Hernandez's fiancee -- at the latter's Boston home, prosecutors say.
They stopped at a gas station and bought things inside. One purchase may be a potentially key piece of evidence: a pack of blue bubblegum.
Prosecutors said that cell phone towers nearby tracked the men's movements. Lloyd had his phone on and texted his sister at 3:23 a.m., likely minutes before his death.
"NFL. Just so you know," he texted his sister to let her know who he was with.
About 3:25 a.m. -- two minutes after the message -- gunshots shattered the quiet night, according to witnesses.
Guns and bubblegum
Not five minutes passed before a surveillance camera captured video of Hernandez carrying a gun as he arrived back at his home, prosecutors said.
He was with two other people. Lloyd was not among them.
A murder weapon is usually a key piece of evidence in a homicide case, and investigators have not been able to find one.
Hernandez at least once had a Glock .45, prosecutors said, entering a cell phone photo into evidence of him posing in the mirror with it.
And police have seized .45-caliber ammunition and an ammunition magazine that were in a Hummer SUV he drove and a condo he rented.
Hernandez and the other two later took the car back to the rental company.
There, the defendant offered an attendant a piece of blue Bubblicious gum, prosecutors said.
What appeared to be a piece of chewed blue gum was left lying inside the vehicle, prosecutors said. Next to it was a spent .45-caliber casing.
The casing matches the empty shells Investigators recovered near Lloyd's body, prosecutors said.
If that gum was in Hernandez's mouth, DNA tests will connect him to the casings, prosecutors said.
When investigators inspected Lloyd's body, they found keys in his pockets to a rental car registered in Hernandez's name.
A fallen star
Hernandez had been expected to be one of the keys to the New England Patriots' stellar offense, a vital cog on a team that many expected could contend for a Super Bowl title.
Now he's sitting in a Massachusetts jail cell.
His stoic expression in videos after his arrest, including when he was in court, gave little indication of angst, sorrow or inner turmoil.
Yet the fact he's behind bars, charged with such a heinous crime, has shaken many in New England.
His former team said firing Hernandez was "simply the right thing to do."
On Friday, the team took another step in cutting its ties to the former University of Florida star, and letting fans do the same. Having already taken his No. 81 off the shelves, the team announced people who had already bought such a jersey could exchange it for free for another player's at the New England Patriots ProShop the weekend of July 6 and 7.
"We know that children love wearing their Patriots jerseys, but may not understand why parents don't want them wearing their Hernandez jerseys anymore," team spokesman Stacey James said. "We hope this opportunity to exchange those jerseys ... will be well-received by parents."
CNN's Ross Levitt, Rande Iaboni and Kim Segal contributed to this report.