On Thursday, Grays Harbor County Sheriff's Office announced Baum's remains were "unknowingly" found by hunters in September 2017. The 10-year-old was last seen the night of June 26, 2009, when she left a friend's home.
Last August, Scott said his office wanted to investigate any possible links between the disappearance and the case of three elderly brothers arrested in Seattle for allegedly possessing images of child sex abuse and other materials detectives say indicate the men spent the majority of their lives sexually abusing children.
He said the Baum family is "understandably devastated".
The results came back matching Baum's DNA. ".Now, the reality is we need to find a homicide suspect".
Now investigators will look for who Scott called a "monster" who apparently abducted and killed her.
Scott did not say where the remains were found or in what condition.
Scott said in 2013 that more than 30 people had been examined as a "person of interest" for varying amounts of time and different reasons, but no one was considered a suspect.
On Thursday, Sheriff Scott again urged the public to come forward with any information that could help in the case.
Most recently, authorities in Grays Harbor County investigated a possible link between Baum's disappearance and three elderly Seattle brothers who were each charged past year with two counts of second-degree possession of depictions of minors engaged in sexual conduct.
Investigators arriving at the home found it covered "floor to ceiling with child exploitative images, children's clothing articles, toys and movies", Senior Deputy Prosecutor Cecelia Gregson wrote in charging documents.
Seattle police also searched a rural, wooded residence near Shelton once occupied by a fourth Emery brother who recently died.
A flyer about Baum was found in the Shelton home, but there is no known connection between the brothers and the disappearance of Baum. Due to the ongoing investigation there was a delay in releasing the information, Scott told reporters.
"There's someone out there we knows who did this and how this happened", Scott said.