Murder suspect watched teenage victim die for 30 minutes, prosecutors say

The disappearance of 19-year-old Sarah Stern took a gruesome turn, according to the New York Daily News.

A 19-year-old man has admitted to strangling the teenager in her Belmar, New Jersey, home for 30 minutes until she died.

The suspect, Liam McAtasney, reportedly told a friend he watched the clock as she died. Prosecutors say he later discussed killing the friend who videotaped his act.

The woman's car was found abandoned on a Belmar bridge in December, and police initially thought she jumped off of it to her death. Now, prosecutors have a different theory.

McAtasney is accused of strangling Stern to death in her home, robbing her of "large quantities of cash," moving the body with the help of his friend Preston Taylor and throwing Stern's body off a bridge.

McAtasney and Taylor, also 19, were arrested face charges related to the murder of Stern.

NBC New York repots that a Crime Stopped tip led police to McAtasney.

The tip alleged that McAtasney somehow knew that Stern had recently withdrawn quite a bit of cash from the bank and came to her house to rob her.

Officials have not yet found Stern's body, and they may never do so.