The suspect, Alan Smith, was arrested Thursday and charged with obstruction of justice. That arrest came a few days after he and his girlfriend, Love Thai, were caught by police having noisy sex in his front yard.
Smith has denied having anything to do with his wife's February death. But Thai tells KOMO News reporter Jamie Lynn that she "absolutely" thinks Smith could have killed his wife.
After Friday's court hearing, Lynn asked Thai, "You live in the home of a horrific murder with the person who's been named the only suspect. ... Is there anything inside you that tells you he did it? He killed her?"
Thai answered, "Absolutely." She went on to say Smith is only human and that we all have our dark sides and our tipping points.
Smith appeared in court Friday, and the judge said he could leave jail if he posts $10,000 bail and gives up his passport. But Thai said Smith doesn't have enough money to post bail. She asked the public to donate money so he could get out of jail.
Smith and Thai have been living in the house where Smith's estranged wife was brutally murdered in February.
He previously was considered a "person of interest" in his wife's slaying, but police on Thursday said he is now considered a suspect. Yet so far he has only been charged with obstruction of justice, after he allegedly declined to give up his passport to police.
At Friday's court hearing, he pleaded not guilty to the obstruction charge.
In an earlier interview with KOMO News, Smith denied having any role in the death of his estranged wife, Susann Smith.
"She was the love of my life for a while and the mother of my children, and my heart breaks," Smith said.
After the murder, Smith moved back into the home where Susann was bludgeoned to death.
Thursday's arrest was Smith's second run-in with the law this week. On Monday, neighbors called police after they heard a woman screaming. When officers arrived, they found Smith and Thai having sex in the yard. Smith was not arrested or cited for the Monday incident.
Thai says she first met Smith soon after Susann was murdered.
"We just had four days of pure bliss and ecstasy and making love for 24 hours, seven days a week and then me sleeping and him cooking for me," she said.
Watch the raw interview: