EPHRATA — A woman implicated in the investigation of Mackenzie Cowell’s 2010 murder successfully appealed an obstruction of justice conviction in Grant County.

Tessa M. Schuyleman, now 24, was convicted by a Grant County District Court judge in March 2011 of misdemeanor charges of giving a false statement and obstructing a public servant. On Wednesday, Grant County Superior Court John Knodell judge overturned the obstruction verdict and sent the false statement charge back for reconsideration by the lower court.

Washington Department of Corrections officers came to the rural Moses Lake home of Schuyleman’s father in November 2010, believing she was harboring a former boyfriend sought for violating terms of his criminal probation. Schuyleman allowed them into the home to search, but the man they sought wasn’t there.

Two DOC deputies then hid on the Schuyleman property and kept watch until Schuyleman left the house and opened an outbuilding, where they found her former boyfriend hiding. She was convicted in March 2011 by District Court Judge Richard C. Fitterer, and sentenced to one day on a county work crew.

Schuyleman’s lawyer Nicholas Yedinak of Wenatchee appealed the verdict, saying DOC officers overstepped when they secretly surveilled the house after pretending to leave. Knodell agreed in overturning the obstruction charge Wednesday, saying the state agents had neither a judge’s warrant nor the needed consent from Schuyleman.

The District Court must now determine whether any evidence remains to support the false-statement conviction.

The obstruction case is unrelated to the Cowell homicide, in which Schuyleman was accused by police — but never charged — of aiding murder suspect Christopher Scott Wilson in concealing the crime.

The Cowell task force arrested Schuyleman in Tumwater in December 2010, while the Grant County case was yet to be heard by a judge. Members of the task force, including director Robbin Wagg of the Douglas County Sheriff’s Office, attended early hearings in the Grant County matter; and Grant County deputy prosecutor Alex Freeburg linked the two cases in arguments before District Court Judge Richard C. Fitterer.

Mackenzie Cowell, a 17-year-old Wenatchee High School student, was found dead on Crescent Bar in February 2010 after she’d been missing for four days. Wilson, now 32, was charged with first-degree murder in her death, but pleaded guilty last May to greatly reduced charges of first-degree manslaughter, first-degree robbery and second-degree robbery. He was sentenced to 14 years in prison.

In proposing the lesser plea, Wilson’s attorney John Henry Browne said jury questionnaires had shown most potential jurors believed Wilson was guilty of the crime. Police said they found Cowell’s blood soaked into the carpet of Wilson’s former apartment, and DNA matching Wilson’s paternal type at the site where her body was discovered.

Schuyleman, a former girlfriend of Wilson, made a cellphone video of his empty apartment that Chelan County’s then-Prosecutor Gary Riesen planned to use as evidence at trial. Her car was seized by police and held for seven months before Yedinak won its return. DNA analysis found no evidence to tie Schuyleman to the murder.

Jefferson Robbins: 664-7123

robbins@wenatcheeworld.com