An Arlington man will spend 26.5 years in prison after a Snohomish County jury found him guilty in the killing of a 37-year-old woman whose body was discovered near Lake Stevens in August 2024. The defendant, Mark Christopher Downey, was convicted in April of second-degree murder after an 11-day trial. Prosecutors said the case largely turned on a DNA match from evidence collected at the scene, backed up by later interviews with investigators. The victim was identified as Katie A. McQueen of Mariposa, California.
The 26.5 year sentence was handed down Thursday in Snohomish County Superior Court, according to KING 5. Prosecutors had urged the court to impose a lengthy term following the jury's verdict and a deadly-weapon finding.
Jury verdict and trial
The jury returned its guilty verdict on April 8 after hearing 11 days of testimony and evidence. HeraldNet reported that jurors found Downey guilty of second-degree murder and issued a special verdict that a deadly weapon was involved.
DNA match prompted arrest
Investigators said the Washington State Patrol crime lab developed a positive DNA match from evidence recovered at the scene in November 2024. That profile was linked to Downey, a break that led to his arrest the same month after months of dead ends. The timing of the match and the resulting arrest were detailed in local coverage and law enforcement releases. KIRO 7 described how the lab work tied Downey to the scene.
Conflicting accounts, eventual admission
According to court documents and police reports cited by local outlets, Downey offered investigators several conflicting stories before eventually acknowledging an altercation that ended with McQueen fatally wounded. Reporting indicates he later admitted meeting McQueen and killing her, then leaving the area, a sequence detectives said was supported by other evidence. Lynnwood Times outlined those shifting accounts as described in the court file.
The scene and the victim
The Snohomish County Medical Examiner's Office identified the decedent as Katie A. McQueen and reported that her body was discovered under brush near the 11800 block of 84th St NE. The office initially listed the cause and manner of death as pending. Snohomish County Medical Examiner records confirm McQueen's identity and the location where she was found. Hoodline carried an early dispatch on the suspicious discovery when the case first surfaced in August 2024.
Background and context
Downey has a prior criminal history that includes an earlier murder conviction as well as more recent sex-offense convictions. Coverage of the case noted he was a registered sex offender living in group housing when investigators linked him to the Lake Stevens scene. HeraldNet detailed those earlier convictions and how they factored into the case.
The Snohomish County Major Crimes Unit led the investigation. Local reporting has consistently highlighted that forensic DNA work by the state crime lab was the turning point that shifted a months-long investigation from unanswered questions to an arrest and, ultimately, a conviction. KIRO 7 emphasized how the lab's DNA match moved the case forward.
.jpg){kind=link}