What happened to missing couple Karen Koep and Davido?

THEOn Nov. 13, police were dispatched to a Washington state couple's home after the wife didn't show up for work.

Soon after, the Thurston County Sheriff's Office announced that Karen Koep and her husband Davido were missing under “suspicious” circumstances.

After several days of interviews and investigative tips, the missing persons case turned into a homicide investigation as officers arrested Timothy Burke on Nov. 17 on two counts of first-degree murder and one count of first-degree kidnapping. The sheriff's office said they “do not believe the couple survived the attack at their residence.”

Now Mrs Koep's sister Pauline Dutton says the couple were generous and selfless people who may have been “taken advantage of” by Mr Burke, who she says was living in one of their rental properties – and facing imminent eviction .

Here's what you need to know about the case:

The disappearance

The Thurston County Sheriff's Office first reported the “suspicious” disappearance of Ms Koep and Davido on November 13.

said Mrs. Dutton The independent she last heard from the couple a few days ago, when she told her sister about Thanksgiving plans.

On November 15, police spotted the couple's car in a nearby town and appealed to the public for help.

At the time, the sheriff's office said “interviews were conducted, surveillance video was obtained and additional follow-up interviews were conducted.”

The murder charges

The latest update came Nov. 17, when police announced they had arrested a 40-year-old suspect from Olympia, Washington who was known to the couple.

Police did not initially name the suspect, but later confirmed he is Mr. Burke to NBC News.

Little is known about the progress in the investigation since the arrest, including what police know about the apparent “assault” and where Ms Koep and Davido would now be if the murder suspicions are true.

Ms Dutton said she had not received any major updates from the police since the arrest, but that she trusted the officers working on the case.

“I trust them,” said Mrs. Dutton. “They take 100 percent care of it.”

The suspect

said Mrs. Dutton The independent Mr. Burke lived in one of the couple's rental properties, a group home rented next door to the room. He said he “gathered” that Burke was doing construction work for Davido instead of paying rent, but could not confirm.

The couple had been preparing to evict Burke until their disappearance, according to Ms Dutton. He said the property where Burke lived “was a source of some stress” for the couple.

“I think they took advantage of the fact that they were kind to this gentleman,” he said.

Karen Koep was an “incredible chiropractor” and an active member of her community, her sister says.

(Pauline Dutton)

Davido – who legally left his surname – had a criminal record and was jailed on drug charges, Ms Dutton previously said The Daily Beast. Arrested in 1993 in connection with a federal passport fraud investigation and spent 72 months in prison after being convicted of possession of cocaine with intent to deliver, The Daily Beast.

said Mrs. Dutton The independent that Davido's “mistakes are in the past” and that he had a “heart of gold”. He described Ms Koep – who worked as a chiropractor in Lacey, Washington – as an active and selfless member of her local community.

“She was not only a physical therapist as a chiropractor, but she was a spiritual mentor and a good friend,” Ms Dutton said. “Connected with patients outside the clinic.”