LACEY, Wash. — A suspect has been arrested in connection to the disappearance of a Thurston County couple, Dr. Karen Koep and Davido, who were last seen on Nov. 13.
The Thurston County Sheriff's Office said the suspect knew the married couple.
Karen Koep's sister, Pauline Dutton, told KING 5 on Sunday the suspect was a "disgruntled tenant" of the couple's nearby rental unit.
"I'm very, very upset over this man who thought he could take such wonderful people from us," a patient of Koep's said.
Koep was a popular chiropractor in Lacey. Many of her patients gathered at the site of her clinic Sunday afternoon to remember and honor them.
"I will say it for everybody who's thinking it: this is messed up," another woman said at the vigil.
In a news release about the arrest, officials said, "We do not believe the couple survived the attack at their residence."
A man in his 40s faces two first-degree murder charges in the disappearance of Koep and Davido.
"They were so selfless and giving to everybody, and I can tell that everybody here's been touched in a deep way," said one of their sons, whom many said was the center of their world. "My dad loved my mother so much."
Koep's patients spoke highly of her as a chiropractor, but also as a friend.
"My 20 minutes a week was probably the sweetest time that I had," said one woman.
"This is messed up, and I look at what her purpose was around here, to take what was messed up and fix it," said another attendee.
"She was a force of nature," added another.
The couple had several family members in attendance, as well as friends.
"He was one of the most giving and selfless people that I have ever met," said one woman, who spoke about her longtime friendship with Davido.
Thurston County's Undersheriff Dave Pearsall is working to investigate the case, but the situation hits home for him.
"You weren't just her patient, you were her friend," Pearsall said.
Pearsall, like many others, was Koep's patient.
Another man at the vigil said, "She gave me words of encouragement when there weren't a lot of people around me at the time."
One woman said Koep even saved her life, and "sent [her] to a cardiologist, begged [her] to go."
She said she first discovered she had heart problems. The cardiologist she urged her to go see later confirmed it.
"They had to do emergency surgery because I was getting ready to have a heart attack, and... I owe my life to her," that woman said.
Another friend and patient said, "God, we're looking for answers."
The investigators are continuing to work on finding Koep and Davido's bodies.
"That will bring our family more closure," Dutton said.
The Thurston County Sheriff calls their search a top priority.
"We're not going to stop until we can give everyone here the closure of finding Karen and Davido, so, that is our promise for you guys," said Derek Sanders, Thurston County sheriff.