Court docs: Man suspected of murdering 58-year-old in Spokane Valley motivated by money

A man stabbed to death in his Spokane Valley home in April was killed as part of a robbery, according to court documents.

A man arrested in early July on suspicion of the April killing of 58-year-old Anthony Plumb was charged with first-degree murder and robbery during his arraignment Tuesday afternoon.

Newly filed court documents reveal how police believe Zane McDonald, 27, went to Plumb’s home, stabbed him twice in the neck and stole several of Plumb’s belongings on the night of April 20.

Police arrested McDonald on July 1 while responding to an unrelated call. He was booked into Spokane County Jail on a $1 million bond.

According to court documents, Plumb’s brother found his body on April 23 in a motor home Plumb had been staying in on North Felts Road. Plumb was house-sitting for the tenant who lived there, and Plumb’s brother was the homeowner.

Spokane Valley police and fire responded to calls of a suspicious death. Medical staff at the scene found Plumb had two gashes on his neck. This was later confirmed by the Spokane County Medical Examiner’s Office, which ruled Plumb’s death a homicide caused by two stab wounds to the neck.

Police noticed several items were missing, including a key to the side door and one of Plumb’s two known cellphones. They collected several fingerprint and DNA samples.

Detectives talked to Plumb’s family and friends, who said he had been a private and security-conscious person unlikely to loan his things. Family members told detectives they believed at the time of his death Plumb kept about $10,000 in a floor safe. Detectives found the safe at the scene, but court records don’t say if the money was inside. Plumb’s brother said he had recently withdrawn the money to buy a new motor home.

Days later, an anonymous caller told police they saw a man they recognized telling people he had $10,000 in cash on him. The caller gave a description of the man along with the man’s nickname, “Mouth Peace,” and police found McDonald matched the details.

Because McDonald had been booked into jail before, detectives could compare his fingerprints to those found at the scene. A forensic specialist said at least one of the prints matched McDonald’s, but was unable to say for certain whether they belonged to McDonald.

In mid-May, McDonald was arrested for an unrelated charge and police asked him about Plumb. McDonald told police he met Plumb about three months prior to Plumb’s death. He said he did go to Plumb’s house around April 20, but he left around dusk and did not steal anything .

He denied knowing Plumb had been killed that same night, according to court documents.

Police got a warrant to search McDonald’s car, where they found several keys. They also interviewed members of Plumb’s family, who said they logged into Plumb’s cellphone account and saw texts and calls from April 21 and 22, after the day Plumb was believed to have died.

Another family member told police they noticed someone attempted to withdraw money from Plumb’s bank account on April 23 – three days after his death. They said a check was made out to another man – not McDonald – for $500, but it bounced. A bank employee confirmed this withdrawal attempt to police, court records say. The 27-year-old man was contacted by detectives but refused to give an interview to police, court records say.

Police found one of the keys they took from McDonald’s car opened the side door of Plumb’s home, the documents say. Another key found in McDonald’s car worked on Plumb’s car. Due to ongoing testing of the floor safe by the Washington State Patrol Crime Lab, detectives could not check if a third key they found in McDonald’s car opened the safe.