When COVID-19 Pandemic Began, Woman Vanished And Started Sending Strange Texts — What Happened To Her?

When the COVID-19 pandemic hit the United States in March 2020, fear and panic spread quickly. One man took advantage of the confusion to try to the hide the murder of his wife.

When Gretchen, a teacher in Jupiter, Florida met personal trainer David Anthony at the gym, they quickly hit it off.

"You definitely watched the sparks fly and you saw quite a bit unfolding," friend Kelly Hanna told "Killer Relationship With Faith Jenkins," streaming now on Oxygen and Peacock. " ... He had a very magnetic personality and she was very drawn to that."

There was one problem: Gretchen was with a man named Jeffrey. They had been dating for many years and had gotten married in 2007. One year later, she met David.

"I know she was unhappy but she had a child with Jeff and they were doing their best to make it work but it didn't and that's when she and David became a couple," Hanna said.

The two tied the knot in 2015, but soon the relationship started to change. David had always dealt with insecurities, his friend Tabitha Hopkins said, and they soon grew stronger. He would have unpredictable mood swings.

"As I started to get to know David better, his moods started to change. There was a definite up and down. He became challenging, I would say difficult," Hopkins who owned the gym David worked at, said.

The marriage became strained to the point where they decided to attend a week-long retreat in Hawaii. But David acted so erratically there he had to be separated from the rest of the group, journalist Eliot Kleinberg told producers.

And in spring 2017, a horrific accident occurred. David was working on his truck in their garage when the jack slipped. He suffered a traumatic brain injury from the car falling on him, and Gretchen had to care for him as he healed from the wounds. David attempted all kinds of methods including gratitude training and self-help groups, but his behavior continued to spiral. In fall 2019, Gretchen and Anthony separated. He moved in with his mom, who lived nearby.

In February 2020, another alarming incident occurred when David came into his work at the gym crying and giving a speech in the lobby about a personal hero of his, Kobe Bryant, Hopkins said. She had to fire him.

A month later, the country was reeling from the COVID-19 pandemic, as people stayed home to isolate and avoid the disease. It wasn't unusual to not see your loved ones during this time — but friends and family were deeply concerned by the texts they started to get from Gretchen on March 23, 2020.

The texts said she had COVID and was so ill she needed to be put on a ventilator. She claimed she was taken to Jupiter Medical Center, and then that she was being transferred to a CDC receiving facility. The facility she spoke of didn't exist.

David Anthony and Gretchen Anthony

Friends and family were alarmed enough to contact law enforcement. Authorities talked to her ex-husband, who confirmed he had her daughter at the moment, but they had been confused by the odd texts, too, and he was concerned it wasn't her actually texting.

They tracked down her car, which was indeed at Jupiter Medical Center. But there was no record of her ever checking into the center. And when investigators went to Gretchen's home, they noted it smelled strongly of bleach and found broken glass on her bed. They also discovered security cameras had been removed from the home. They contacted the company to retrieve the footage from the home, but had to wait for it to come through.

Authorities were concerned they had been unable to find David Anthony. They learned David had actually changed his name and been hiding a secret past.

"There were things he didn't want people to know. He was not the fun-loving, free-spirited, charismatic trainer people knew as David Anthony," Dave Aronberg, a state attorney in Palm Beach County, Florida said. His actual name was David Anthony Deutsch. In the past he had assaulted a police officer and held up a video store.

And just seven days before Gretchen went missing, police had responded to a report of a man acting suspiciously and approaching teenage girls in a parking lot. They found a man packing back and forth and acting agitated — it was David Anthony. He was arrested, but eventually posted bail. He'd been missing ever since.

Authorities soon discovered something even more disturbing — Gretchen and David's cell phones were pinging on the same path, traveling through Texas and New Mexico. Once he was in New Mexico, local officers were able to detain him. He claimed he had no idea where Gretchen was, and they had to let him go.

But investigators continued to work the case, and on March 29, 2020, David called police in Florida. He claimed he was with Gretchen and she was fine.

"Gretchen is scared for her life. She uncovered illegal federal tax fraud. Someone was sent to her house to hurt her the other weekend," he claimed in audio obtained by "Killer Relationship." He added that her employer was the issue, and she had contacted the IRS and had been in communication with OSHA.

When investigators contacted local agencies, they learned Gretchen hadn't made any reports like that. The allegation against her employers was completely fabricated by David.

Finally the service provider of Gretchen's security cameras was able to retrieve the footage from the cloud. It clearly showed a tall, dark figure on her porch at about 6 a.m. the morning she disappeared. Gretchen eventually answered the door, and a struggle ensued. Gretchen was dragged to the garage, where investigators could see she had stopped moving and there was blood in her hair.

Her assailant looked into the camera. It was David Anthony.

Gretchen's final words were captured, too: "Alexa, call 911," she begged. Unfortunately, she hadn't set Alexa up for this command.

On March 31, 2020, David was arrested and charged with kidnapping and second-degree murder, although the charge was eventually upped to first-degree.

David continued to insist he and Gretchen had split up around El Paso, Texas, and that she was alive. Detectives still didn't have a body, so a plea deal was eventually reached. David would be sentenced to 38 years in prison if he told them where Gretchen was. On December 21, 2020, nine months after Gretchen went missing, he pleaded guilty to second-degree murder.

Gretchen had been buried at the grounds of an assisted living facility. An autopsy revealed she had been stabbed multiple times.

"Our hearts are forever broken ... Gretchen saved your life when your call fell on you yet you killed Gretchen in the same garage … you are pure evil. You are a monster," a loved one read in a statement at David Anthony's sentencing.

For more on this case and others like it, watch "Killer Relationship With Faith Jenkins," streaming now on Peacock and Oxygen.