New Jersey man describes to police how he and roommate threw childhood friend Sarah Stern’s body over bridge to steal her money

In video recorded by detectives not seen or heard outside a courtroom, a New Jersey man who pleaded guilty to helping his roommate dispose of the body of high school friend Sarah Stern, reenacted for investigators how the two had tossed her body over a bridge in 2016.

On video released to ABC News, Preston Taylor told detectives Stern was slumped in a corner of a bathroom, “tucked into the corner and leaning over the toilet,” when he went to Stern’s house one night in December 2016.

Taylor, then 19, told investigators that he went there "to move Sarah's body" and "to keep watch and make sure everything went smooth."

On Tuesday, a Monmouth County jury found McAtasney, 21, guilty on all seven charges against him, including first-degree murder, robbery and desecrating human remains.

McAtasney believed Stern found more than $50,000 in cash hidden in a box in her family’s second home, authorities said.

Prosecutors argued that McAtasney killed Stern in order to steal money she discovered after her mother died from cancer and then later enlisted Taylor to help him remove her body from her home and throw her into the Shark River from a bridge connecting Neptune and Belmar, New Jersey.

Stern’s body was never found, but police discovered her abandoned car on Dec. 3, 2016, on the Route 35 Bridge with the keys still in the ignition hours after she went missing.

Group of friends called ‘The Squad’

Taylor, McAtasney and Stern were in the same circle of friends at Neptune High School. Taylor was Stern’s date to junior prom.

In December 2016, Taylor and McAtasney were living together and both attending community college.

After Stern’s disappearance, her friends were grappling with the possibility that she could have jumped from the bridge, committing suicide.

McAtasney also had told investigators that she’d talked about taking the money and moving to Canada.

But, in January 2017, the Monmouth County Prosecutor’s office set up a sting operation. They placed a recording device inside McAtasney’s friend Anthony Curry’s car and captured what they said was a confession by McAtasney to the murder of 19-year-old Stern.

“We went to the bank. She took some money out — not all of her money ... she goes to walk out the front door. I choke her out, dragged her,” McAtasney said in the recording, which authorities have called a confession. “It took me a half an hour to kill her … then we threw her out the bridge.”

The recording was the first time authorities learned that McAtasney didn’t act alone and that he had an accomplice — Taylor.

When detectives brought Taylor in for questioning, he cracked immediately, admitting that he knew McAtasney had killed Stern.

Taylor said he was just getting home on Dec. 2, 2016, when McAtasney gave him the grim news.

“He was like, ‘Dude, I did it,’” Taylor said during his interrogation. “He said that her body was still at the house and we had to get rid of it tonight.”

Taylor takes authorities back to bridge

“I don’t know if I’ve ever seen anyone confess that quickly,” prosecutor Chris Decker said. “He goes on for, you know, 52 pages or something in a transcript of describing [what] they did.”

Taylor agreed to return to the scene of the crime — Stern’s house — and show authorities on video what he and McAtasney had done.

“It’s powerful,” Decker said. “He was willing to go back there, to this place where he had done some pretty awful things, and show the detectives how they (he and McAtasney) did this and how they did that.”

On the tape, Taylor said he’d carried and then dragged her until he sat her body under some bushes.

After McAtasney went back into the house, Taylor said his car was loaded with the safe that held the cash that Stern had withdrawn from the bank that day, and McAtasney’s car had Stern’s body inside.

On a later date, detectives were once again rolling tape as they took Taylor to the Route 35 bridge.

Wearing a green jumpsuit, handcuffed and shackled, Taylor walked around the bridge discussing how he and McAtasney had disposed of the body of their friend.

“Liam was going to throw the body over himself and then run across and jump over the median and get in the passenger seat of my car,” he said in the recording. “He wasn’t strong enough to pull Sarah up and over himself, so he radioed me on the walkie-talkie and told me to loop around and to come help him get her over.”

Taylor told investigators that McAtasney had lifted Stern’s body by the shoulders and he had grabbed the legs.

“She went over, immediately over. Her body was up and over the rail. As we were running back to my car ... we heard a loud, metallic bang and that was all,” he said.

“Preston wishes he had acted differently. Preston has cried with me. Preston has now tried what he could to try to atone for himself,” his attorney John Perrone told "20/20."

“He knows that whatever he does, he can't bring her back. But he could try though — through his efforts to help police,” Perrone said.

Taylor reveals the location of the stolen money

Taylor said the empty safe had been buried in Shark River Park. The money, he said, had been buried in another safe near Hartshorne Woods Park.

Detective Brian Weisbrot said Taylor directed police in February 2017 to a location just east of the lighthouse in Sandy Hook, New Jersey.

There, the investigators found a small, gray safe with the number 002 stamped on it. As investigators uncovered the safe containing the money, police were taking McAtasney into custody and searching his car.

On McAtasney’s keychain was a key and on the backside of the key were the numbers 002, Detective Nick Cattelona said.

“The fact that Liam had the safe key for the safe that was buried with Sarah’s money at Sandy Hook is an amazing piece of evidence,” Decker said. The key was successfully able to open the safe. According to Cattelona, $9,350 in cash was found in the buried safe.

Taylor also later told investigators that he’d stashed some items found in Stern’s safe, including a key to a safety deposit box Stern had at Kearny Bank in Bradley Beach, New Jersey.

The items, according to Taylor, were hidden inside the heating vent in a back bedroom in his former home.

According to Cattelona, Stern had two keys to the box and the key found in the vent matched the safety deposit key found in her car.

The money in the buried safe was identical in condition to the more than $25,000 in cash in Stern’s safety deposit box at the Bradley Beach bank. The cash was older currency and rotting and falling apart, according to Cattelona.

Last month, during McAtasney’s murder trial, Taylor testified against his former roommate. In his testimony, he admitted to having conversations with McAtasney about ways to get Stern's money.

"They started off as plans to burglarize her house, or to rob her, personally. Over time, the conversations progressed to killing her, in order to obtain that money," Taylor said on the witness stand. "Specifically, it was decided that Liam would strangle her. Any type of weapon would have been too messy, would have left a whole lot of evidence."

Taylor pleaded guilty to first-degree robbery, second-degree conspiracy to commit robbery and second-degree disturbing or desecrating human remains.

As part of his cooperation agreement with prosecutors, the state dropped a felony murder charge against Taylor.

Taylor faces between 10 years and 20 years in prison. He and McAtasney will be sentenced in May.