Defendant Liam McAtasney looks toward his family during his murder trial at the Monmouth County courthouse in Freehold, N.J. McAtasney is accused of killing Sarah Stern in December 2016. (Patti Sapone/NJ Advance Media/Pool/AP)

A passing Uber driver was the first to spot the abandoned Oldsmobile and sense that something was wrong. It was after midnight on Dec. 3, 2016, and the silver sedan was parked at the crest of the bridge that connects Belmar and Avon-by-the-Sea, N.J., two beachfront communities separated by the chilly Shark River that flows out into the Atlantic Ocean. There was no indication that the car had broken down before being deserted by its owner, and when police officers arrived, they found the keys still in the ignition.

As police started looking for the missing driver, Michael Stern was becoming increasingly concerned that his 19-year-old daughter, Sarah, hadn’t answered any of his texts.

“Sarah, where are you?” he wrote, according to the Asbury Park Press.

“Sarah, are you up?”

“Sarah, what’s going on?”

At first, it looked like a suicide. Investigators quickly learned that the 1994 Oldsmobile belonged to Sarah Stern’s grandmother, and that the teenager hadn’t been seen or heard from since the previous afternoon. Coast Guard helicopters, rescue boats and dive teams searched the estuary but came up empty-handed, and the river’s fast-moving current made it more than likely that a falling body would have been swept out to sea. When officials questioned one of Stern’s oldest friends, the portrait that emerged was one of a troubled young woman desperate to get out of her small New Jersey town.

“I just know she’s been trying to get away, been telling me she’s moving to Canada,” Liam McAtasney told officers when they knocked on his door. McAtasney had been friends with Stern, an aspiring artist who had recently dropped out of community college, since elementary school. According to the Press, he told police that she had threatened to kill herself at least once before, and that she had “trust issues” with her father, who was “crazy” and had stolen money from her at least once. The two had been arguing continually for the past few months, he added, and Stern had been talking about needing to get away as their relationship deteriorated.

Two months after Stern disappeared, however, police made an arrest that shocked the quiet seaside community where she had once played on the high school softball team and worked a local pizzeria. McAtasney, then 19, was charged with strangling his childhood companion and recruiting another friend, Preston Taylor, also 19, to help cover up the murder by staging it as a suicide. The two men had joined the search parties that combed the Jersey Shore in the wake of her disappearance, the Press reported. Taylor had taken Stern to junior prom, and the three had been part of a “big, happy group” at Neptune High School, Michael Stern told the paper in February 2017. “Don’t know what happened,” he said. “Something. I guess people change. … Sometimes for the better, sometimes for the worse.”

The reason for the change, according to prosecutors, was that McAtasney learned about a shoe box full of cash that Sarah Stern’s mother had left behind when she died of cancer four years before.

The dog-eared bills, totaling roughly $25,000, had been stashed in the family’s second home in Avon-by-the-Sea, unbeknown to Stern’s father. After finding the box, Stern had used the windfall to take trips to Florida and Canada, pay for surgery for her dog and buy a television for her grandmother. Then, at her aunt’s urging, she had put $5,200 in a checking account and the rest in a safe-deposit box at a bank in Bradley Beach, N.J.

Not knowing that he was secretly being recorded, McAtasney confessed to a friend in January 2017 that he had believed there was anywhere from $50,000 to $100,000 in the shoe box. In the video, which authorities played in court Thursday, he complained that Stern had only about $10,000, which appeared “burnt or something” and was so old-looking that he didn’t even know that he could deposit it in the bank.

The chilling tape, in which McAtasney appeared to describe plotting Stern’s murder for six months before strangling her and faking her suicide, was the latest piece of evidence presented by prosecutors in the ongoing trial, which began last month in Monmouth County, N.J. Although Stern’s body still has not been found, McAtasney, now 21, has been charged with homicide and faces life in prison. He has pleaded not guilty.

To Stern’s family and friends who testified in court, the idea that she could have killed herself or left for Canada without telling anyone had never made sense. She had been happy in the days leading up to her disappearance, they all agreed. Besides, her aunt testified, Stern would never have left behind her beloved dog, Buddy.

But the key break in the case came when Anthony Curry, a horror film director and a friend of McAtasney’s, told police about a conversation the two had on Thanksgiving night in 2016, a week before Stern’s disappearance.

“He told me he was going to meet up with Sarah, she had found this money,” Curry, 21, testified on Thursday, according to NJ.com. “They were going to count it together. He was going to choke her, choke her out. Bring her to the bridge, throw her off, and Preston was going to drive the escape vehicle. And they were going to bury the money and leave the keys in the ignition and make it look like she killed herself.”

Police set up a hidden camera in Curry’s car, and he made plans to meet McAtasney on Jan. 31, 2017, singing along to “Bad Reputation” by Joan Jett and “Rock‘n Me” by the Steve Miller Band on the way to calm his nerves. He parked on a residential street not far from the beach, and McAtasney hopped in the passenger seat, commenting that he was hiding from the cops. Later, he told Curry that he had “enough to live comfortably in my house and throw parties all the time” but that the haul hadn’t been as much as he had expected.

With no apparent remorse, McAtasney described choking Stern until she had a seizure, then stuffing a shirt down her throat while he covered her nose. After a half-hour, he said, he put her body in the passenger seat of the Oldsmobile, backing out of the driveway in the same way that he had observed her doing so that no one would notice that someone else was driving her car.

“My biggest problem was the dog,” he said. “Her dog laid there and watched as I killed her. Didn’t do anything.”

Carlos Diaz-Cobo, McAtasney’s defense attorney, had an explanation ready for the seemingly damning video. Earlier in the trial, NJ.com reported, he said his client had been auditioning for a role in one of Curry’s slasher movies, not confessing to murder. The dialogue in the video was a script that had been made up to impress the young director, he claimed.

But the details all matched previous testimony from Taylor, who in April 2017 pleaded guilty to charges including robbery, disturbing human remains and tampering with evidence. In exchange for a reduced sentence, he agreed to testify against McAtasney, his former friend and roommate, who he described as a “Manson-like person.”

The two had initially discussed burglarizing Stern’s house, Taylor said in court last month, according to the Press. One night, he said, McAtasney had brought over a six-pack of Mike’s Hard Lemonade and tried to get Stern drunk so that they could steal her money. But she told him that she had put the money in a safe-deposit box, forcing them to come up with a new strategy. Finally, he testified, McAtasney had persuaded her to take the cash out of the bank by persuading her that he wanted to go on a trip or even move away from New Jersey with her.

The plan from there was simple: McAtasney would strangle Stern, then call Taylor on a walkie-talkie. In exchange for helping dump her body off the bridge, he would get a $3,000 cut. The stories about Stern having a troubled relationship with her father and being emotionally unstable were all lies that McAtasney had cooked up to make it look as if the 19-year-old had killed herself, Taylor told the court.

The defense has tried to undercut the credibility of Taylor, the state’s star witness, by pointing out that he lied to police by claiming that he had been sexually assaulted as a child in an apparent bid for sympathy, NJ.com reported.

“His testimony is untruthful, it’s false, it’s imagined, erroneous and not credible,” Diaz-Cobo said at the trial’s start, according to the Press. In his own testimony, Taylor said that it had been McAtasney’s idea to lie about a childhood rape in an attempt to gain pity.

He also recalled the words that McAtasney had used when he first told him about the shoe box that their former classmate had found: “It’s the type of money that somebody would kill for.”

More from Morning Mix:

'It’s all about the Benjamins baby’: Ilhan Omar again accused of anti-Semitism over tweets

A ‘mass invasion’ of polar bears is terrorizing an island town. Climate change is to blame.

‘Freedom never tasted so good’: How Walter Jones helped rename french fries over the Iraq War