The body of missing Marie Singleton-Jackson was discovered after a man spotted her gray Saab parked at Dockweiler State Beach in Los Angeles.

On Nov. 16, 1994, CIA employee Marie Singleton-Jackson was found dead in the trunk of her car.

The 33-year-old mother had vanished five days prior, and a man who saw her missing persons flyer spotted her gray Saab parked at Dockweiler State Beach in Los Angeles.

There were two parking citations on the dashboard, the sunroof was slightly open and the battery had been ripped out. Singleton-Jackson's cell phone and purse were in the car, which was still locked.

Investigators towed her car for inspection, and when they broke into the trunk they made a startling discovery. Singleton-Jackson's body was curled in a fetal-type position, and there was bruising on her face. An autopsy report later found that she had died of strangulation

More of her personal effects — including credit cards and jewelry — were also found in the trunk, leading investigators to believe her death was not the result of a robbery gone wrong.

The fact that the battery had been removed from the car also made authorities theorize that whoever killed Singleton-Jackson wanted her body to be found.

When detectives from the Inglewood Police Department returned to the station, Singleton-Jackson's husband, Andre Jackson, was waiting in the lobby. Former detective Russell Enyeart told Jackson that they had found Singleton-Jackson's body, and Jackson appeared to be devastated.

“Andre threw himself to the floor and started screaming. Russ described to me, he said it was as if a 2-year-old was having a tantrum and banging their fists and feet on the floor,” Homicide Detective Steve Seyler told “A Wedding and a Murder,” airing Thursdays at 9/8c on Oxygen.

Authorities were skeptical of Jackson’s emotional outburst, and they became even more suspicious after another detective ran into him at a nearby car wash following the death notification acting as if nothing had happened.

In an interview, Jackson said that on the night his wife vanished, they had plans to attend his son, Andre Jackson Jr.’s, high school football game. Singleton-Jackson had been drinking, however, and said she was too intoxicated to go, according to Jackson.

He then reportedly left her at home, and she was missing when they returned.

Jackson filed a missing persons report the next day around 10 a.m., telling authorities that she and her car were gone.

By accessing Jackson’s phone records, investigators learned he had made only one call to his wife the night she went missing, which they found extremely odd.

“When somebody cannot reach a loved one, they will absolutely go nuts blowing up their phone lines,” Deputy District Attorney John Lewin told “A Wedding and a Murder.”

Marie Singleton

Friends also told detectives that after the couple married in early 1994, Jackson became controlling of his wife, and the marriage was falling apart. While Jackson claimed the relationship was going well, he had told some friends that Singleton-Jackson had been seeing another man.

Just a few days before she was killed, Singleton-Jackson told her husband that she was working at an offsite location, but he later found out she had lied and took the day off. Jackson was furious, and it led to another argument.

“It indicates to me Andre seemed to be watching her pretty closely,” Seyler said.

Although detectives focused on Jackson as the main suspect in Singleton-Jackson's murder, there was not enough evidence to charge him. Skin flakes had been recovered from underneath her fingernails and a drop of blood from the hood of the car, but DNA testing was still a relatively new technology.

Singleton-Jackson's autopsy evidence was placed in a file and the case went cold for nine years until 2002, when the FBI reopened the investigation along with the Inglewood Police Department cold case team.

Detectives wanted to interview Singleton-Jackson's eldest son, Marcus, who was 8 at the time of the murder and hadn't spoken to police. Marcus told Seyler that on the day of his mother’s murder, he was watching TV alone, and she had come into the room, said something and left.

He eventually went downstairs and saw his 8-month-old half-brother alone in his play pen crying. Neither Jackson, his stepfather, nor his mother was there.

Marcus also said that their marriage was crumbling, and that Jackson had become controlling and abusive with his mother. He recalled one fight on Oct. 1, 1994, that got physical, with Jackson putting a hand over his wife’s mouth and another around her throat.

In subsequent interviews with friends and family, detectives learned that Singleton-Jackson had been making plans to leave Jackson about six weeks before she was killed. She also had a meeting with the children and told them they might separate.

Armed with new information, investigators obtained a warrant for Jackson’s DNA. When they couldn't find him, they tracked down his son, Andre Jr., to make a potential familial match.

Cold case investigators submitted Andre Jr.’s DNA sample, the blood drop from the car and the fingernail evidence to the FBI crime lab, and it came back as a familial hit. In April 2008, 14 years after Singleton-Jackson's murder, Jackson was found in Arizona and charged with first-degree murder.

He stood trial in 2012, and the prosecution theorized that on the night of the murder, Singleton-Jackson had told her husband that she wanted to separate — and he had responded by strangling her to death. He then put her in the trunk of her Saab and parked it at the beach, removing the battery so no one would move the car.

It took the jury three hours to find him guilty, and he was later given 25 years to life in prison, reported local CBS affiliate KCLA.

To learn more about how investigators tracked down Jackson and hear from Singleton-Jackson's family, watch “A Wedding and a Murder” on Oxygen.