Lane County Man Gets 10 Years for Killing Mother's Fiancé

Sean Joseph Lynn received a 10-year prison sentence in Lane County Circuit Court after pleading guilty to second-degree manslaughter in the shooting death of Derrick Adam McKee, the 49-year-old fiancé of Lynn's own mother. Judge Jay McAlpin imposed the sentence on March 11, the same date that would have been McKee's 51st birthday. McKee was present in the courtroom; his ashes were carried in an urn by family members.

Barbara Lynn, Sean's mother and McKee's fiancée, opened her victim statement to the court with three words: "Happy birthday, Derrick." Lynn faced each of the seven people who read impact statements, nodding and shaking his head as they spoke tearfully before Judge McAlpin.

The shooting occurred on August 19, 2024, at the home the three shared on the 33000 block of Coleman Road, north of Coburg near Interstate 5. According to court documents, tensions had built up in the household over time through disagreements about rules and personal matters before erupting into a confrontation that day. Barbara Lynn reported that McKee kicked down her son's bedroom door and threatened him before she heard shots. Lynn emerged and told her he had shot McKee in self-defense. She took the firearm from him and called police.

Multiple agencies, including the Lane County Sheriff's Office and Oregon State Police, responded to find McKee dead on the bedroom floor, shot multiple times. Detectives arrested Lynn the same day.

Lynn, 32, was originally indicted by a Lane County grand jury on one count of second-degree murder. He pleaded guilty on January 26, one day before his trial was set to begin, after prosecutors agreed to reduce the charge to second-degree manslaughter, a Class B felony carrying a maximum of 10 years under Oregon law. In pre-sentencing filings, his public defender, Caitlin Plummer, wrote that had the case gone to trial, "the central issues would have been whether Mr. Lynn's use of his firearm was justified as self-defense, and/or whether he was acting under the influence of an extreme emotional disturbance." Lynn had told investigators that McKee warned he would "knock him out," advanced with a balled fist, and shoved him onto a bed before the shooting.

Court documents described Lynn as having no prior criminal history. The 10-year sentence matched the recommendation made by both prosecutors and the victim's attorney, and Lynn will receive credit for approximately 19 months already served in Lane County Jail.