“Help.”

Brittany Dawn Killgore’s text pinged her friend’s phone at 7:50 p.m. It was April 13, 2012, but the one-word text didn’t seem like a Friday the 13th prank. Not coming from Killgore, the pretty San Diego-based wife of a Marine serving in Afghanistan. And not now, just three days after she had filed for divorce.

Worried, the friend texted back, asking if Killgore was all right. Two hours later she got a response.

“Yes I love this party.”

The text didn’t seem like Brittany, the friend thought. It was too flippant and used “yes” instead of her usual “yeah.”

That’s because it wasn’t from Brittany. By that point, Brittany was dead.

Four days later, Killgore’s naked body was found near Lake Skinner 70 miles north of San Diego. Her neck showed signs of strangulation. Her wrists and ankles appeared as if they had been bound. She had several small burn marks from an electronic stun device. And one of her legs had been cut after death, as if her killers had tried to dismember her corpse.

If the brutal crime shocked San Diego, its investigation shook the city even further. Police arrested a Marine staff sergeant from nearby Camp Pendleton base. Then they arrested two women, one of them pregnant, for allegedly assisting in the murder.

When the case finally went to court last month, the crime grew darker still. Prosecutors laid out in excruciating detail how Killgore had been murdered as part of a sadomasochistic sex kidnapping. Marine Louis Ray Perez had tricked her into hanging out with him, then he, Dorothy Grace Maraglino and Jessica Lynn Lopez kidnapped, sexually assaulted and killed Killgore to satisfy their fetishes, prosecutors claimed.

On Wednesday, almost three and a half years after Killgore’s death, all three suspects were convicted of murder, kidnapping, torture and attempted sexual battery by restraint.

“Our daughter was a beautiful young woman inside and out, and unfortunately she ran across people that were not good, were monsters and took her life,” Killgore’s mother, Michelle Wrest, said after the verdict, according to the San Diego Union-Tribune.

Wrest also thanked San Diego Sheriff’s detectives for “keeping us from completely losing our minds.”

It was a maddening case, one that stemmed from the darkest, most dangerous fetishes of the three murderers.

Maraglino and Lopez lived together in a house in Fallbrook, Calif., north of San Diego. Perez, a burly Marine in his mid 40s, was a frequent visitor. The three engaged in bondage, whipping, cutting and spanking, among themselves and with others, NBC reported, citing search warrants. They had “play sessions” with needles, knives and ropes. The house even had a sex dungeon just for that purpose, equipped with “bondage type sex apparatuses, toys and tools,” investigators later found.

Perez and Maraglino, who was in her mid 30s and pregnant at the time, had a dominant-submissive relationship, according to court testimony, the Union-Tribune reported. Lopez, in her mid 20s, was Maraglino’s “slave.”

Killgore, meanwhile, was the wife of a young Marine. She and her husband had moved to San Diego from Missouri, but now she was on her own while he was in Afghanistan. She was unhappy, apparently, and filed for divorce.

Three days later, Killgore reluctantly accepted Perez’s invitation to accompany her on a cruise of the San Diego harbor. She thought the outing was platonic and phoned Maraglino to make sure it was all right.

But Perez’s plans were not platonic, and things would not be okay.

Perez picked Killgore up at her apartment, but he didn’t head to the harbor. He drove to the sex dungeon.

Thirteen minutes later, Killgore texted her friend “Help.”

It was the last her friend would hear from her, although she would receive odd texts purporting to be from her two hours later.

“Yes I love this party,” one read. “It’s OK. Music is too loud,” said another.

Neither one was from Killgore. She was already dead, stunned into submission by Perez and killed in the sex dungeon when the S&M trio’s bloody fantasy went awry — or, more chillingly still, went according to plan.

Her body was discovered near the lake four days later by a tractor clearing brush, according to ABC News 10. By then, Perez was already under arrest. As the last person seen with Killgore, the Marine staff sergeant quickly had been questioned by police. During the interview, cops spotted an assault rifle that had been reported stolen. When they asked him about Killgore, Perez was uncooperative, officials told the Los Angeles Times.

Two days later, the same day cops discovered Killgore’s body, police also arrested Lopez. She was holed up in a Point Loma hotel room. But rather than hiding out, Lopez appeared to be served to authorities on a silver platter. With her in the room was a letter she wrote confessing to murdering Killgore out of fear that she would upend the sex ring by seducing her master, according to warrants, CBS reported. In her letter, Lopez appeared to absolve Perez and Maraglino, who she called her “Master” and “Mistress.” The letter claimed Lopez shot Killgore with the stun-gun, wrapped a rope around her neck, strangled her, and then tried to dismember her with Perez’s power tools before dousing the body with bleach and leaving it near the lake.

In court, however, Lopez’s lawyer told the jury that her client’s letter was simply her fulfilling her role as a “slave” to Perez and Maraglino by taking the fall for a crime she didn’t commit.

“She was known as ‘money b—-,”‘ her attorney, Sloan Ostbye, said in court, according to San Diego 6. “Her role was not unsimilar [sic] to that of a dog.”

The other two members of the S&M sex ring also turned on one another during the month-long trial.

Perez’s attorney told jurors that Lopez committed the murder out of jealousy, according to San Diego 6. Meanwhile, Maraglino’s lawyer claimed her client had abandoned her old BDSM ways while pregnant, and that she had simply assisted in covering up the crime.

Ultimately, the jury decided that all three were to blame for the twisted crime. Perez, Maraglino and Lopez now face life in prison.

After the trial was over, Killgore’s mother thanked prosecutors, detectives and jurors for finally giving her daughter justice.

“She is going to be missed,” Wrest said, “for the rest of our lives.”

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