FREEHOLD BOROUGH — The last defendant in the Sarah Stern murder case was sentenced Friday to 18 years in prison for his role in the 2016 slaying.

Preston Taylor, 22, will have to serve 15 years before he is eligible for parole. He had been facing a max of 20 years as a result of a plea deal in which he helped prosecutors lock up his friend for the rest of his life.

Taylor and Liam McAtasney, 21, were convicted of killing the 19-year-old at her Neptune City home and then throwing her body off the Route 35 bridge, where they left her car to make it appear like a suicide. Stern's body has never been found.

After the sentencing, Stern's father, Michael, said it was "just evil" and dismissed Taylor's courtroom apology, saying that anybody who had a "conscience and a soul" would not have participated in the plot.

"If you get to be 19, if you don't know right from wrong, good from bad, there's something wrong with you," he said.

Preston Taylor looks back at his family after he is sentenced to 18 years for his role in the demise of Sarah Stern in the courtroom of Judge Richard W. English at the Monmouth County Courthouse in Freehold, NJ Friday June 28, 2019.

Taylor pleaded guilty and agreed to testify against McAtasney, who denies killing Stern despite a chilling confession captured in a secretly recorded video. In the video, McAtasney said he choked Stern to death, keeping track of the minutes as he watched her struggle and urinate herself.

McAtasney's lawyer argued that the taped confession was an act to impress a horror filmmaker friend.

Liam McAtasney in a secretly recorded video in which he confesses to killing Sarah Stern in 2016. (NJ.com via YouTube/File photo)

Taylor testified that the murder plot was meant to steal Stern's cash inheritance from her mother, which McAtasney also explained in the undercover video.

Taylor and McAtasney were roommates and had been friends with Stern. The three had attended Neptune High School together and Taylor and Stern attended their prom as a couple.

On Friday, Taylor apologized for being part of the plan and wished he had done more to stop it, according to Asbury Park Press coverage of the sentencing.  According to the Press, Sarah Stern's father Michael walked out of the courtroom when Taylor began to speak and returned when he was done.

Liam McAtasney is sentenced to life in prison with no chance of parole for the murder of Sarah Stern in the courtroom of Judge Richard W. English at the Monmouth County Courthouse in Freehold, NJ Friday June 21, 2019. ASBURY PARK PRESS PHOTO BY TANYA BREEN

Michael Stern said Taylor also should have gotten life in prison but Monmouth County Prosecutor Christopher Gramiccioni said Taylor's cooperation was vital to the case.

"There are situations where unfortunately you have to get in the mud with people that are culpable for the crimes that you’re trying to prosecute," Gramiccioni said after the sentencing. "I’m confident but for that assistance and cooperation we would have struggled to make the conviction against Liam McAtasney and be able to ensure that he stays in prison for the rest of his life without a chance of parole."

Michael Stern, father of Sarah Stern, makes a statement before Preston Taylor is sentenced to 18 years for his role in the demise of Sarah Stern in the courtroom of Judge Richard W. English at the Monmouth County Courthouse in Freehold, NJ Friday June 28, 2019. (Tanya Breen/Asbury Park Press pool photo)

As part of his plea deal, Taylor admitted helping McAtasney throw Stern's body off the bridge when McAtasney was unable to lift it. Taylor said that McAtasney told him if that if he was ever questioned about Stern’s disappearance, he should say she had had a falling out with her father and had attempted suicide.

Taylor pleaded guilty in May 2017 to charges of first-degree armed robbery, second degree conspiracy, second-degree desecration of human remains, third-degree hindering apprehension of oneself, third-degree hindering apprehension of another and fourth-degree tampering with evidence.

McAtasney was sentenced last Friday to life in prison with no chance of parole for the murder. He was sentenced to concurrent terms of 20 years for first-degree robbery and five years for third-degree hindering. He must first serve a consecutive 10-year sentence for disturbing or desecrating human remains.

It was the mandatory sentence for the conviction in the December 2016 slaying.

Contact reporter Dan Alexander at Dan.Alexander@townsquaremedia.com or via Twitter @DanAlexanderNJ

Sign up for the NJ1015.com Newsletter

Get the best of NJ1015.com delivered to your inbox every day.