EVERETT — A second teenager has admitted to being part of a drug robbery that resulted in the death of a woman in December.
Mondrell Robertson, 18, pleaded guilty in Snohomish County Superior Court to second-degree murder on Sept. 20.
Robertson faces up to 18 years in prison at sentencing, which is set for Dec. 4. Prosecutors and defense attorneys have agreed to recommend a 10-year sentence.
He is one of two defendants who have entered pleas in the case. They both have agreed to testify against three others who remain charged with murder.
Robertson was among a group of five people who went to Julie Knechtel’s house to rob her 17-year-old son, whom they knew kept drugs outside in a shed. They broke into the shed, knocked her son to the floor and began punching him, according to prosecutors. One of the attackers pistol-whipped the son.
Knechtel was shot when she tried to intervene. Her son was then shot in the back. He survived his injuries.
In new court papers, Robertson said he was not armed and did not shoot either victim, but he knew going into the robbery that two of the people with him had guns.
As part of the plea, the prosecutor won’t pursue charges against Robertson for aggravated first-degree murder. If convicted, that offense carries a mandatory life sentence or capital punishment.
Robertson also won’t face trial for a drive-by shooting that took place earlier in the night, according to court papers.
On the way to the robbery, the same group of teens allegedly fired shots at a south Everett apartment complex. A 15-year-old girl was nearly struck as she opened her bedroom window, records show.
Four other defendants in the case have pending hearings.
Bryan Rodriguez-Hernandez, 17, pleaded guilty in August. He admitted to shooting and killing Knechtel. He faces up to 35 years in prison. He is scheduled to be sentenced Nov. 29.
Larry Dontese Dorrough, now 17, is accused of shooting Knechtel’s son in the back. He has a hearing on Oct. 5, with a trial set for later in the month.
A trial for Gladyz Valencia-Anguiano, 17, has been moved to next year.
Under state law, she and Rodriguez-Hernandez, Dorrough and Robertson were prosecuted in adult court because they were 16 or 17 at the time of the killing.
Another boy, who was 15, is scheduled to appear before a judge on Tuesday. It has not been determined whether his case will proceed in adult or juvenile court.
Reporter Rikki King contributed to this story.