Death in the Dorms: Inside the murder of University of Miami linebacker Marlin Barnes

From a 20-year-old Jackson State University accounting major who was stabbed and left in a wooded area, to an 18-year-old who died just 24 days into his freshman year at Louisiana State University, the deaths of university students can be especially tragic. The new season of ABC News Studios' "Death in the Dorms" follows the stories of six young people who were in the prime of their lives, set to embark from college life to the "real world," when their lives were cut short.

Marlin Barnes grew up in Florida housing projects, dreaming of playing football at the University of Miami, according to his mother, Charlie Postell.

"I did not want to stay in government housing with my children -- I wanted better for them and they deserved better. I gave it my all," Postell said. "Marlin was probably 17 when we bought our house and we moved to Miami Gardens. The neighborhoods that we came from, they were dangerous neighborhoods -- but we survived."

Watch the ABC News Studios six-part series, "Death in the Dorms," which tells the tragic stories of six college students whose lives were cut short by violent crime. The series begins streaming exclusively on Hulu on Feb. 22.

"Marlin was the first child in our family -- period -- to go to college," she said. "Everybody was proud and he was the happiest kid on Earth."

Once Barnes began his football career at the University of Miami, he thrived, his mom said.

In the spring of 1996, he was voted the most improved player.

Weeks later, on the night of April 12, 1996, Barnes was invited to a party at Club Salvation, and he brought his childhood friend, Timwanika Lumpkins.

Barnes had borrowed his roommate’s car, and when Barnes and Lumpkins left the club at the end of the night, they found the tires had been slashed. So the friends waited for a tow truck to pick them up and headed back to Barnes' place.

The next morning, Barnes’ roommate, Earl Little, arrived home to find Barnes and Lumpkins viciously beaten.

Barnes, 22, was declared dead at the scene and Lumpkins, also 22, died on the way to the hospital, officials said.

Flora Seff, then a Miami-Dade assistant state's attorney, described the slayings as "brutal."

"The blood had spattered up to the ceiling, to the walls," Seff said.

An unused shotgun shell was found at the scene, Seff said, as was what looked to be a shotgun trigger guard, according to true crime podcast host Taylar Fetzner.

"I just lost it," Barnes' mom said. "I was just baffled. I was sitting there thinking, who would want to hurt him?"

"[Police] wanted to know if Marlin had any enemies, if he had gotten into any fights or arguments," she said. "The answer was no. … He was a great kid."

Once the investigation was underway, Lumpkins’ boyfriend, Labrant Dennis, went to speak with police.

"He basically said, 'I didn’t have anything to do with it, I lived with her, I loved her, we have a baby together,'" Seff said.

But Dennis also told investigators their relationship was off-and-on, said Fetzner.

Dennis told police that about one week before the murders, Lumpkins moved out. The two got into a fight because she had come home late, and Dennis believed she’d been hanging out with Barnes, Fetzner said.

When she moved out, Dennis was convinced Lumpkins went to stay with Barnes, Fetzner said.

"In the media coverage, it was portrayed as though Marlin and Timwanika were a couple behind Labrant’s back -- they were friends," Barnes’ mother said. "He was lending a helping hand to someone that asked him for help."

"When I was told that he moved her to get her out of the abusive relationship, I was not surprised, because I had done the same thing for someone years before," she said.

Dennis told police that on the night of the murders he ended up at the same club where Lumpkins and Barnes were, Seff said. Dennis told police he didn’t see Lumpkins and Barnes there, and eventually he went home, Seff said.

Investigators zeroed in on the area around Club Salvation, and they found a strong witness: a woman who worked at a nearby gas station.

The woman told police a man had been sitting in a gray Nissan in the gas station parking lot that night, and when she asked him to leave, he wouldn’t, Seff said.

The gas station attendant said she called police, and when the officers responded, the driver "took off," Seff said. But when the police left, the man returned to the parking lot, Seff said.

The mystery man left for good later in the night.

Investigators showed the gas station attendant a photo of Dennis’ car -- but it wasn’t a match, Seff said.

Police also looked into whether gangs could’ve been behind the attack because Barnes volunteered with the Right Track Foundation.

"The purpose of the Right Track was to inspire children from low-income areas -- such as [the project] where Marlin grew up -- to leave the gangs behind," Fetzner said.

"Whoever had done this was willing to get up close and personal with their victims and brutally attack them at a very close range," she said. "So investigators had to find a way to prove if this motive was true: Was there a gang member that had targeted Marlin and wanted him gone?"

Police eventually learned that the Nissan at the gas station was registered to Watesha Wallace -- a girlfriend of Labrant Dennis, said Seff.

Then, the big break in the case came when Dennis' co-worker, Joseph Stewart, called a police tip line.

Stewart said on April 7, he lent Dennis his mother's shotgun, Fetzner said.

On April 13, Dennis called Stewart to say he returned the shotgun and left it in the bushes outside his mother’s home, Stewart told police.

When Stewart opened the bag left in the bushes, he found a knife and clothing -- as well as the shotgun, which was now damaged and missing the trigger guard, Fetzner said.

On April 30, Labrant Dennis was arrested for the murders of Timwanika Lumpkins and Marlin Barnes.

"I think he waited for Marlin to come out [of the club]," Seff said. "He just couldn’t control himself -- slashed the tires, he followed the tow truck, he sees the car, sees the building they get into. So he brought that shotgun."

"When Labrant got inside, when the shotgun did not work," Fetzner said, "[I think] he was so committed to ending both Timwanika and Marlin’s lives that night he brutally beat their faces in with the butt of the shotgun -- so badly that he broke [the gun]."

Barnes' mother, Charlie Postell, happened to work with both Stewart and Dennis at the Dural Golf Resort and Spa.

"I used to talk to him about my son," she said. "I just couldn’t put it together."

Barnes’ mom said she attended every day of the trial.

"The trial was hard. I didn’t look at any of the pictures -- I didn’t want to see them," she said. "I listened to the testimony that everybody gave. His defense was that Joseph [Stewart] could have been the one that committed the murders because it was his shotgun. It was, you know, heart-wrenching to hear that."

Dennis was convicted of all charges, including two counts of first-degree murder and one count of burglary.

In the penalty phase, the jury recommended the death penalty with a vote of 11-1.

Dennis was sentenced to death in 1999.

In 2016, the Florida Supreme Court ruled to reopen multiple death row sentences based on how many jurors voted in favor of the death penalty. And in 2020, the Florida Supreme Court upheld the reversal of these death penalty convictions and Dennis was moved off of death row.

Since the 2020 ruling, prosecutors in Florida have been asking for Dennis' death sentence to be reinstated. Dennis' possible return to death row is pending a review by the court.

For Barnes' mom, the reversal felt like "we’re being murdered again."

"Labrant chose to kill my kid. He nearly killed my family -- but we survived it," she said. "We’re going back to court to have the death penalty reinstated. That’s what we’re fighting for now."

"I don’t want people to just dwell on the way my son passed, because I do enough of that for everybody," Postell added. "I try to remember the person that he was -- the happy person that he was."