By Eric Mandel
emandel@covingtonreporter.com

Two parties responsible for the murder of a 39-year-old Kent woman, who was found in the trunk of her burned car near Black Diamond, have been sentenced to prison.

Kent residents and co-defendants Kennon Fastrup, 32, and Michelle Backstrom, 37, were sentenced Friday, with Fastrup receiving 45½ years in prison and Backstrom sentenced to 12½ years.

A jury convicted Fastrup last month on charges of first-degree murder, second-degree arson, attempting to elude and violation of a no-contact order. Backstrom pled guilty in March to a charge of second-degree murder.

According to the King County Prosecutors, the pair murdered Denise Grigsby, 39, in May 2012 after an argument.

According to the charges, the murder occurred May 4 at Backstrom’s home on the East Hill, after an argument between Fastrup and Grigsby.

Grigsby’s body was found two days later, shortly after 4 a.m., when Mountain View Fire and Rescue responded to a report of a car fire in the area of Southeast 328th Street and Southeast Auburn-Black Diamond Road. The fire department found Grigsby’s Toyota Camry fully engulfed in flames, with her body, burned beyond recognition, in the trunk. Grisby was eventually identified through her dental records.

The couple was arrested May 11 in North Bend after a high-speed car pursuit. Investigators said they had been camping out in the woods near I-90 after the killing and car fire.

Following their arrest, Backstrom confessed to detectives that she had participated in the murder and arson, saying an argument among the three turned physical, moving from the kitchen to the garage. There, Backstrom claimed in the charging documents, Fastrup struck Grigsby in the head with a flashlight while Backstrom also punched. She stated that Fastrup strangled Grigsby with a braided metal cable, and when the cable became too slick with blood, Backstrom strangled Grigsby with a key lanyard, while Fastrup continued to strike the victim in the head.

The King County Medical Examiner’s Office determined that Grigsby died from blunt force trauma to the head.

According to the charging documents, Fastrup denied participating in the murder, but confessed to burning the car. He claimed he did it at the request of Backstrom and did not know Grigsby was dead, or that her body was in the trunk, until they actually arrived at the scene and he opened the trunk. He said he burned the car anyway to assist Backstrom.

All three individuals were believed to be abusing methamphetamine.

Fastrup and Backstrom had lengthy criminal histories, according to Senior Deputy Prosecutor Kristin Richardson. Backstrom had been released from prison two years prior to this incident following a vehicular homicide conviction. Fastrup had previous convictions for attempting to elude, assault and drug and firearms violations.

“This was a brutal, harrowing murder with a hideous aftermath,” Richardson said in an email. “The convictions of these defendants will not bring back Denise Grigsby, but they delivered justice, and the community is safer as a result.”