A couple arrested in the disappearance of a 20-year-old South Carolina woman were charged with murder, police announced Monday morning.

Heather Elvis, of Myrtle Beach, S.C., was last heard from in the early morning hours of Dec. 18, after she went on a date. Her 2001 Dodge Intrepid was found abandoned the next day on the Peachtree Boat Landing in Socastee, Horry County.

Tammy and Sidney Moorer were arrested Friday after authorities executed a search warrant at their home near Socastee.

In addition to being charged with murder, the couple faces kidnapping, obstruction of justice and indecent exposure charges, WMBF reports.

Horry County Police Chief Saundra Rhodes said Monday that during the search, police found evidence that gave them probable cause to charge Tammy and Sidney Moorer with murder.

She added that authorities have not located Elvis.

"That is something that we are still looking for,” Rhodes said, according to WMBF.

Cellphone records show Elvis communicated with Sidney Moorer, 37, as late as 6 a.m. on Dec. 18. Police records also state that Elvis had a relationship history with Moorer.

Investigators said Elvis was driven home by her date to the apartment she shared with another woman in River Oaks some time before 2 a.m. on Dec. 18. The young man with whom Elvis met for the date has been ruled out as a suspect, a source close to the investigation told FoxNews.com. Authorities believe that at some point later, Elvis drove herself to the boat landing, though the reason remains unknown.

A task force of about 15 investigators has been assigned to the case, including two Myrtle Beach police detectives and individual investigators from the U.S. Marshal's Office and FBI.

Authorities, as well as more than 300 volunteers, have scoured heavily wooded areas surrounding the boat landing for any sign of Elvis since her Dec. 18 disappearance.

Anyone with information on the case is urged to call the Horry County Police Department at 843-915-5350.

Click for more from Fox Carolina.

FoxNews.com’s Cristina Corbin contributed to this report.