Heather Elvis, a 20-year-old hostess at a popular restaurant in Myrtle Beach, vanished in South Carolina on Dec. 18, 2013.

UPDATE September 18, 2019:

CONWAY, S.C. (WSOC/AP) -- A judge has sentenced a South Carolina man to 30 years for kidnapping a woman he was having an affair with who hasn't been seen for nearly six years, WSOC-TV reports.

A Horry County jury found Sidney Moorer guilty Wednesday. His wife, Tammy Moorer, began serving a 30-year sentence for kidnapping Heather Elvis in October.

Prosecutors used cellphone records, Facebook posts and security camera footage to show Sidney Moorer and his wife were at the Horry County boat landing where Elvis was last seen in December 2013.

MORE: Man gets 30 years for kidnapping woman missing since 2013 - WSOC

UPDATE October 23, 2018:

A jury has found Tammy Moorer guilty of kidnapping and conspiracy to commit kidnapping in connection with the December 2013 disappearance of Heather Elvis, WMBF reports. Moorer was sentenced to 30 years in prison on each of the charges. The sentences will run concurrently.

UPDATE June 24, 2016: Jury unable to get past deadlock. Judge declares mistrial, WMBF reports.

UPDATE March 10, 2016: Murder charges against Sidney and Tammy Moorer dropped; kidnap charges still pending

December 10, 2015:

In an exclusive interview with Crime Watch Daily, this is the first time that Heather's best friend and roommate Brianna Warrelmann has ever spoken on camera. Brianna and Heather were working together when Sidney Moorer, a 38-year-old maintenance man caught her eye.

"She was like 'Do you see him?' And I was like, 'Who?' 'Sidney.' I was like, 'Who is Sidney?' 'That guy over there, the maintenance guy,' and I was like, 'really?'," said Warrelmann. "And she just sat there and blushed as she talked about him. Even after that day, the day they first started talking, over a series of weeks it was her being like, 'Bri, Sidney did this and we hung out here,' and every time he would come in she would almost run away. 'Sidney's here' kind of thing."

Heather's romance with Sidney was brief but very intense.

There was one big problem: Sidney Moorer is a married man. According to Brianna, Sidney's wife Tammy Moorer knew about the affair and told Heather to stay away from her man.

"When the whole thing was found out, it blew up like a bomb almost," said Brianna. "Tammy was livid, texting Heather, sending Heather pictures of her and Sidney having sex. I personally never saw them. I told her I did not want to. Tammy and her phone calls, 'You're going to stop talking to my husband or else.' It wasn't 'or else I am going to do this' -- it was 'Or else!' So it wasn't like Tammy had specifically said a threat, necessarily -- it was, 'Leave my family alone.'"

According to Brianna, Tammy made sure Heather got the message loud and clear.

"Tammy called Heather and said, 'You're going to end it with my husband,' and so she put Sidney on the phone, sat there while Sidney and Heather talked," said Brianna. "They ended things on the phone but Sidney made comments to Heather and said 'You were nothing to me, you were just someone who spread your legs' and basically tore Heather apart as a human being, and who she was as a person and made her feel horrible about herself."

Two months later, Heather showed signs she was moving on from her bitter breakup. She called Brianna, who was out of town visiting family, that she was going on a date.

"It was supposed to be the first official date since after her relationship with Sidney had ended," said Brianna. "I asked her what they were going to do and she said, 'Not sure but just excited.'"

Heather was happy that night, and let those close to her know it.

"She texted me during the date," said Brianna. "She said, 'My date is teaching me how to drive manual car.'"

"I got a text from her somewhere between 9 and 10," said Terry Elvis, Heather's father. "Was a picture of her driving a truck and it was a stick-shift 'cause she always wanted to learn how to drive it, and she sent me a picture, it says 'Look at me, I'm a pro.'"

No one knew this would be the last picture anyone ever saw of Heather. Heather's date dropped off heather at her apartment around 2:30 a.m.

Around 3 a.m., Brianna gets an emotional phone call from Heather.

"She was crying," said Brianna. "And when I asked her what was wrong, she told me Sidney had called her."

Brianna was floored when heather told her why he called.

"'He said he left his wife, he missed me and wanted to see me.' I was like, 'Don't ruin it, don't throw away how far you've come in the past month or so for him,'" said Brianna. "She was like, 'I know, it's just so hard. I don't know what to do. I was like, 'How about you sleep on it.' She was like, 'OK, I'm going to play on the computer more and then go to sleep and I will talk to you tomorrow.' We always end our conversation with 'Love you.' So we said 'Love you,' hung up and that was the last time I talked to her."

According to police reports, Heather then left her apartment and drove to the Peachtree Landing, a popular place for fishermen and kayakers in Socastee, S.C. For some reason she parked her car there at 3:38 a.m.

"Peachtree Landing is literally in the middle of nowhere," said Brianna.

The next evening the police get a call of a suspicious vehicle parked oddly at Peachtree Landing. It's Heather Elvis's car, but is registered to her father, Terry. The cops go pick up Terry and bring him back to figure out what's going on.

"I came with the officer to identify the car and to open it for him, I had the spare keys to it, so we got here, we found the car, we opened the car, the officer went through it and we found receipts and time-stamped earlier that day, and that's pretty much it," said Terry Elvis. "We searched the entire area for anything else that had been discarded or dropped, and found nothing. He spoke to his supervisor, we made a lot of phone calls to determine what had happened and where'd she go."

Heather Elvis had vanished along with her car keys, purse and cellphone.

"We called over and over and over went straight to voicemail," said Terry.

"Every time. Which is not Heather," said Debbi Elvis, Heather's mother.

Horry County Police wanted to meet with the last person Heather called or texted. According to police reports, it was Sidney Moorer. Terry also had access to Heather's cellphone records and wanted to talk to him as well.

Cops questioned Sidney and told the cops he had not spoken to Heather for at least two months. That was not true. According to a police reports, Sidney then backed up on his story and admitted he did speak to Heather, but only to tell her to quit calling him.

Police began searching for Heather. They talk to Heather's date, the last known person to have seen her, and he is cleared of any wrongdoing. Sidney and his wife Tammy claim they were home the night Heather goes missing. As word began to spread that Heather was missing, many volunteers stepped up to find her.

Then the search for Heather goes from sad to bizarre and at times downright scary.

After months of searching for Heather, police would not find the missing girl, but they would find two suspects.

A little more than a month after Heather went missing, police had to shift their focus to two South Carolina men who may have jammed up the investigation.

Police accused Bill Barrett of trying to run his own investigation and questioning witnesses connected to the case. Cops also claimed he found potential evidence and did not immediately report it to the authorities.

Police also arrested Garrett Starnes for fabricating misleading information about heather Elvis's disappearance and then sending it to law enforcement. The information was posted online and diverted investigators from the case.

Both men were charged with obstruction of justice. Garrett Starnes was freed after a judge dismissed his case, and Bill Barrett's day in court was pending.

Sidney Moorer later filed police reports alleging someone took a shot at his family -- not once but twice. Just hours after Sidney's second run-in with a gunman, the cops show up at his house with a search warrant.

Sidney and Tammy are also both arrested and charged with obstruction of justice, and in a bizarre twist, two counts of indecent exposure for "marital relations in public." The cops claim the charges are related to the Heather Elvis missing-persons case.

Days later, more charges are piling up for the Moorers. The police announce that the couple is charged with the kidnapping and murder of Heather Elvis, even though her body hasn't been found.

The prosecution for the case laid out a preview of the case against the Moorers during their bond hearing. According to police records and court documents, Tammy began harassing Heather via phone calls and texts after she found out she was having an affair with her husband Sidney. The prosecution also came up with a timeline during those crucial hours before Heather disappeared.

Police determine that early on the morning of Heather's disappearance, after a few attempts to reach Sidney, Heather gets a hold of him at 3:17 a.m. Police determine Heather is still at her apartment and Sidney is still at his house. Investigators believe after this conversation, heather gets into her car and drives three miles to Peachtree Landing.

At 3:36 a.m. a private residence camera captures a dark-colored truck coming from the direction of Sidney's house headed toward Peachtree Landing. Another camera at a business location records the truck getting closer to Heather.

From Peachtree Landing, Heather repeatedly calls Sidney's cellphone 3:38 a.m. to 3:40 a.m. Then at 3:41 a.m. not only do the phone calls stop, but Heather's phone goes dead.

At 3:45 a.m., the same black truck identified by police is the same vehicle heading back in the direction of the Moorers' house. Video surveillance cameras capture it all. The police believe that black truck belonged to Sidney and Tammy Moorer. Sidney's attorney stated to the press that there is not enough evidence to positively say the truck is the same one that belongs to the Moorers. The video cameras never capture the license plate.

A Horry County judge issues a gag order shutting down attorneys, the cops and court officials from talking to the press.

Sidney and Tammy had now been held without bond for several months. Their attorneys convince a judge to allow them out on bail for $100,000 each.

It's now been almost two years since Heather went missing and the most-talked-about murder trial in South Carolina has not begun. Numerous delays have only increased speculation as to the strength of the prosecutor's case.

In another shocker, a judge has allowed Sidney and Tammy to move from their home in South Carolina to Florida until the start of the trial.

No date has been set for the trial of Sidney and Tammy Moorer.

For a detailed timeline of the events of the case, visit station partner WMBF-TV in South Carolina.

March 10, 2016 UPDATE: Murder charges against Sidney and Tammy Moorer dropped; kidnap charges still pending

If you have any information in the disappearance of Heather Elvis, you can submit a tip to Crime Watch Daily online or call our tip line at (844) 800-CRIME.