A King County Superior Court judge sentenced a 31-year-old Kent man to 18 years in prison for fatally stabbing a man in a Des Moines apartment for having an affair with his girlfriend.

Kyle Michael McCullough pleaded guilty as charged to second-degree murder with a deadly weapon enhancement in the June 17, 2022 killing of David Aguayo, 26, at the Des Moines Station Apartments, 2060 Kent Des Moines Road, according to court documents. McCullough then reportedly dumped Aguayo’s body in a tote along the side of a road near the Duwamish River in Skyway.

Judge Matthew Lapin sentenced McCullough to 16 years for the murder and two years for the deadly weapon enhancement on Feb. 28 at the Maleng Regional Justice Center in Kent. McCullough pleaded guilty Dec. 19, 2024. Prosecutors recommended 171 months on the second-degree murder charge but the judge decided on 192 months. The judge also ordered McCullough to community custody for three years after his release.

McCullough’s statement said he stabbed Aguayo at least two times with a knife with a blade longer than 3 inches, according to court documents. Aguayo was stabbed inside an unit of the apartment complex that sits just west of Pacific Highway South and north of Highline College.

“After discovering that his girlfriend had an affair with the victim, the defendant went to where the victim was staying and stabbed him multiple times, to include stab wounds to the face, head and genitalia,” wrote Senior Deputy Prosecuting Attorney John Castleton in charging papers.

King County Sheriff’s Office deputies contacted the Des Moines Police June 20, 2022, advising them about a dead body dumped near the river in the 13500 block of Beacon Coal Mine Road South.

A man who shared the apartment with Aguayo told Aguayo’s sister that he had found him stabbed to death in the apartment and that he helped dispose of the body in a large plastic tote, according to charging documents. He then told the sister where to find the body.

The woman went to the location and saw a tote wrapped in tarps. Prior to looking inside it, she called 911 to report it. Sheriff’s Office deputies responded and found the body.

Des Moines Police applied for a search warrant for the Des Moines apartment as well as a dumpster on the property. Detectives found several items that appeared to have blood on them, including a rug located in the dumpster, according to charging papers.

The roommate told a detective that Aguayo had been “couch surfing” at his residence on and off for a few months. He said on June 17, 2022 he woke up to the sound of someone yelling. He got up and saw Aguayo lying on his back on the floor and McCullough bent over the top of him, according to charging documents. He said McCullough was holding a knife.

Over the next few hours, the roommate said McCullough cleaned up the floor and removed Aguayo’s body from the apartment. He reportedly put the body in a large tote used to store a Christmas tree.

Detectives interviewed the girlfriend of McCullough at their Kent apartment. She said early in the morning of June 17, 2022 there was a dispute among her, McCullough and Aguayo because McCullough had just found out the two were sleeping together, according to charging papers.

A photo was taken on the girlfriend’s phone by McCullough that showed his girlfriend and Aguayo laying on the floor of the apartment together. The text associated with the photo was sent to Aguayo’s phone number and read, “U lucky to be alive.”

On June 18, 2022, the girlfriend told police she came home from work and noticed a white plastic garbage bag on the floor that was not there when she left, according to court papers. McCullough was not home at the time. Inside the bag was a long-sleeved shirt, red/black pajama pants, a camouflage folding knife and a roll of black electrical tape. She recognized the pajama pants as belonging to McCullough and the knife belonged to her. She didn’t recognize the shirt.

The girlfriend showed detectives two text messages she received from McCullough on June 18, 2022 in which he threatens to kill her and her friends, according to charging papers.

Des Moines Police used a search warrant on McCullough’s Kent apartment in the 6200 block of South 238th Place. They reportedly found bloody socks and other items that appeared to have blood on them.

Des Moines Police arrested McCullough June 22, 2022 at his Kent apartment. During an interview with detectives, he admitted to stabbing Aguayo during a physical fight but claimed he did so in self-defense, according to charging papers. He said he stabbed Aguayo with his girlfriend’s knife. He said he did not call 911 to aid Aguayo and that he watched him die before starting to clean the apartment.

McCullough said Aguayo’s body was still on the floor when he left and he denied moving the body from the apartment.

A detective said a county medical examiner reported that Aguayo sustained more than a dozen stab wounds as well as at least two gunshot wounds and that one of the stab wounds entered his cheek and severed his carotid artery. There was black electrical tape wrapped around the body inside the tote consistent with the type of tape collected in McCullough’s apartment, according to charging papers.