Renton man accused of killing partner with machete

Ten months after he was released from prison for an assault charge that landed him about 17 years, a Renton man who allegedly killed his romantic partner in Seattle has been charged with murder.

On July 9, the King County Prosecuting Attorney’s Office charged Willie James McCoo Jr., 55, of Renton, with domestic violence first-degree murder. McCoo’s next hearing is a July 23 arraignment, where an initial plea is entered.

According to charging documents, McCoo was in a romantic relationship with Kiara Sewell, 31, when sometime between June 9 and June 15, he is accused of killing her. According to documents, June 15, Sewell’s body was found inside an apartment at the Aries at Bitter Lake Apartments, 900 N. 143rd St., Seattle.

Documents state that Sewell appeared to have suffered multiple injuries on her body that were likely caused by a sharp, heavy blade. Additionally, portions of her left arm were amputated, and her left hand was missing and has still not been found.

According to the King County Medical Examiner’s Office, Sewell died on June 10. Additionally, the office reported that her cause of death was multiple sharp force injuries, and her manner of death was homicide.

Documents state that security video from the apartment complex shows the last time Sewell was seen alive was on June 9, when she entered the apartment with McCoo, but she was never seen leaving again. According to documents, McCoo was seen entering and leaving the apartment multiple times holding bags days after Sewell was last seen.

In prosecutor Gretchen Holmgren’s request for a $4 million bail, she cited that McCoo’s most recent criminal conviction came in 2008 when he was found guilty at trial of domestic violence first-degree assault. She said that McCoo received a high-end sentence of the sentencing range and was released from prison in August 2024.

“The incident took place in 2005, when he attacked a woman he was romantically involved with, stabbing her several times and partially transecting her carotid artery,” Holmgren said. “She was in critical condition when rushed to Harborview Medical Center and suffered permanent injury to her vocal cords.”

According to the King County Department of Adult and Juvenile Detention jail lookup portal, McCoo was arrested on July 7 and booked into the King County Correctional Facility. McCoo remains there on a $4 million bail.

Details of the case

According to documents, at about 11:43 a.m. June 15, officers responded to the Aries at Bitter Lake Apartments when they received a call that a body was found. Documents state that officers entered the unit and found Sewell deceased, but no others.

The owner of the unit was arrested in February and is in-custody out of state. According to documents, Sewell and McCoo were reported to have been squatting at the apartment.

Sewell was found to have been assaulted multiple times, likely by a heavy blade. Documents state that the medical examiner ruled that a machete most likely caused the injuries, and she had died days before she was found.

Based on video surveillance from the apartment complex, McCoo and Sewell were seen at approximately 2:42 a.m. June 9, and McCoo was not seen leaving again until 1:52 a.m., June 10. According to documents, McCoo was then seen alone, entering and leaving the apartment multiple times between June 10 and June 12.

McCoo was arrested on June 27, pursuant to a search warrant, and his work locker was subsequently searched. Documents state that inside his work locker, a duffle bag was found that he was seen carrying on the video from the apartment complex.

Inside the bag were an about 18-inch machete and an about 11-inch hunting-style knife. Documents also state that the person who conducted Sewell’s autopsy said that the marks on Sewell’s body were consistent with injuries from a machete like the one found in McCoo’s locker.