Investigators Focus In On Slain Nurse's Boyfriend, But Who Is The Real Killer?

La’Rene Austin burst into the Los Angeles County Sheriff's station in Palmdale, California with a harrowing story.

The woman told detectives she had gone to her best friend LaNell Barsock’s house on the afternoon of June 16, 2010 to finish weaving her hair when she slipped on something slick in the garage.

She soon discovered she was lying in Barsock’s blood.

“I’m looking at the blood … and then when I looked I saw her legs,” said Austin, who was covered in blood herself when she arrived at the sheriff’s station.

Barsock had been lying face up on the garage floor with a black plastic bag over her head.

Deputies rushed to the scene of Austin’s large 3,400-square foot home and found the 29-year-old dead at the scene, according to “Dateline: The Last Day,” streaming on Peacock.

She had been shot in the back of the head.

“Usually when somebody puts a plastic bag or any type of covering over a victim’s face it means they don’t want to see that person or they don’t want that person who is deceased watching them, so we made the assumption that whoever had done this killing knew the victim,” said now-retired Los Angeles County Sheriff’s Det. Bob Kenney.

Detectives also discovered bloody bedding shoved into the back of LaNell’s open car trunk and indications the killer might have been trying to load the body into the car before giving up and leaving LaNell splayed on the floor of the garage.

Back at the sheriff’s station, Austin had given investigators a clue about who the killer might be, telling authorities that after she slipped in the blood, she had heard someone in the house.

“I heard somebody walking upstairs … and he was like coming down the stairs and I looked, and I just ran out the door,” she said in the interview tape, telling authorities the man had looked like LaNell’s live-in boyfriend Louis Bonheur.

The couple had met at school, where LaNell had been taking nursing classes and Bonheur, who had immigrated from Haiti, was taking an English as a second language course.

LaNell, who was known for her kind and generous nature, had offered Bonheur a ride home as he stood waiting at the bus station. The pair quickly hit it off.

“Their love blossomed between them,” Bonheur’s close friend Phillipe Louis-John told Dateline’s Josh Mankiewicz.

But investigators would soon learn that Bonheur also had a jealous streak.

Several people told detectives that Bonheur often went through her phone to see who she was texting, texted people back pretending to be LaNell to see what they’d say and called any number he didn’t recognize. He even went as far as staking out her job at lunch time to see who she ate with and checking with her employer to confirm that she had shown up to work.

“There was a dark side that people didn’t know about Louis and that was that he was a very jealous and controlling individual,” retired Los Angeles County Sheriff’s Det. Joe Espino said.

Just months before her death, the local sheriff’s office had been called to the couple’s home for a domestic disturbance, although there had been no physical injuries and no arrests were made.

That same month, LaNell’s mom, Bobbie Barsock, told investigators that LaNell had tried to break up with Bonheur and he had allegedly gotten in his car, followed her and tried to run her off the road.

“She called me on the phone…she said, ‘Louis tried to run me off the road, momma. … And she was screaming, screaming,” Bobbie said in an interview recording obtained by “Dateline: The Last Day.”

According to Espino, Bonheur had collided into her vehicle, scraping the side of her car with his truck and shattering her windows.

On the day she was killed, Austin—who told detectives she had known LaNell for 10 years—told detectives she had texted her friend in the morning around 9:34 a.m. to see if she could come to LaNell’s home in Palmdale to finish doing her weave.

She arrived at the home not long after sending the message. While the girls had planned on a beauty day, Bonheur left to meet Austin’s boyfriend to get his truck fixed in Los Angeles, a drive that would typically take about an hour and a half.

Earlier that week, Bonheur had been angry when he discovered that LaNell had a secret cell phone she was using to text another love interest, a Sacramento flight nurse named Ike she had met on a dating site.

After Bonheur made the discovery, LaNell promised to end her clandestine relationship with Ike, however, on his drive to meet Austin’s boyfriend, Bonheur discovered that the relationship was not over.

“He was told the phone is dead and he finds out the phone is not dead, somebody has added minutes to it, so he turns around to go back to confront LaNell with this newfound information,” Kenney said.

He returned home around 11:30 a.m. that morning and an argument between the troubled couple broke out.

To break the tension, LaNell and Austin decided to leave the house to go get some beauty products around 12:05 p.m. but Bonheur followed them to the store. Austin told detectives that the continued to argue, until LaNell handed over the secret cell phone she had taken from him at the house.

With the phone in his hand, Bonheur calmed down and returned home, while Austin and LaNell picked up some food before heading back home.

According to Austin, the peace between the couple didn’t last long and she told investigators that LaNell and Bonheur started to argue again shortly after they returned home.

Frustrated, she told detectives she decided to leave the home around 1:25 p.m. to give the couple some space and walked to a nearby park, where she spent several hours before returning around 6:30 p.m. to make the grisly discovery.

According to Austin, she ran out to her car in a panic. When she couldn’t find her cell phone, she drove to the closest sheriff’s station to report her friend’s death, claiming that Bonheur had been chasing her along the drive.

It didn’t take long for authorities to track Bonheur down. He had been at LaNell’s mom’s house in Los Angeles, sleeping.

Bonheur, who had a scratch along his face, admitted to following the two women to the beauty store that day, but he said he left to go back to Los Angeles around 12:40 p.m. and arrived at Austin’s boyfriend house around 2 p.m. Together they went to several auto parts stores to buy parts before he went to LaNell’s mom’s house to stay the night around 6 p.m. so that he didn’t have a long commute to work the next morning.

He insisted that he and La’Nell had a good, loving relationship.

Investigators weren’t so sure and confronted Bonheur with a break-up letter signed by LaNell that had been found at the house. The letter said that LaNell was leaving him for Ike because “he makes more money.”

“We’re getting married so just leave me alone,” it said. “I have been sleeping with him for 4 months now.”

During the interrogation, Bonheur claimed that he had never seen the letter and seemed genuinely distraught to learn that his girlfriend had been killed.

“Oh my God, that’s not right,” he sobbed. “That’s not me, that’s not me, that’s not me. Why they do that to her? Oh my God.”

He pleaded with investigators find her killer. Even with the emotional plea, Espino said authorities still believed they had their killer and arrested Bonheur for the slaying.

Detectives were shocked to later learn that his alibi checked out, and he’d been captured on surveillance footage that afternoon at several auto parts stores miles away from the crime scene.

“The lights start to go on that we’re heading in the wrong direction,” Kenney said.

Investigators went back to what they knew about the case and discovered that much of the initial narrative had been provided by Austin, who claimed to have been a childhood friend of LaNell. Yet LaNell’s mother didn’t recognize her when they passed each other at the sheriff’s station.

Espino was also troubled by her account that she had just spent hours in the park that June afternoon in sweltering heat, alone, before returning to LaNell’s house that evening.

“We asked her what are you doing at that park and she said that she sat there, watching the children play,” he said.

Authorities had also found two bullets in her purse the night she had rushed to the sheriff’s station and later discovered that Austin owned the same type of gun used to kill LaNell.

They found physical evidence at the scene, including a bloody footprint on a rug and a plastic container with a bloody fingerprint that were linked to Austin.

Even more surprising, detectives learned that the women had not known each other for years as Austin described, but had met just weeks earlier after Austin had put an ad on Craigslist for women seeking women.

Espino said the women had been involved sexually, but that LaNell had ended the relationship just shortly before her death.

LaNell hoped that the women were going to stay friends—and expressed as much in a text message earlier that week—but Austin had other plans and shot LaNell in the back of the head while doing her hair, then forged a break-up letter to Bonheur to mislead authorities.

“It was very apparent that La’Rene had far stronger feelings for LaNell than I think LaNell even knew,” prosecutor Jason Quirino said, adding that Austin had been obsessed with her, impersonating her on other dates and trying to take over her persona.

Austin fled before detectives were able to arrest her, but after she was featured on “America’s Most Wanted” she was tracked down in Belize and apprehended.

Austin was convicted in 2015 of first-degree murder and is serving two terms of 25 years to life.

"Dateline: The Last Day" is available to stream on Peacock, with new episodes dropping Tuesdays.