A man from Idaho has been sentenced to a lengthy prison term for the gruesome murder and dismemberment of a man he had been stalking. The perpetrator, Alan Douglas Bruce, reportedly sent a letter to the victim’s daughter, suggesting that by dismembering the victim’s still-missing body, he had done them a favor by reducing funeral costs.

Alan Douglas Bruce, aged 70, received a 20-year prison sentence for the killing of 47-year-old Patrick Shelton, as per court documents. Bruce confessed to charges of second-degree murder and tampering with evidence last month. The investigation by the Custer County Sheriff’s Office began on May 10 when Shelton failed to return from a wood-cutting trip.

According to an arrest affidavit obtained by Boise NBC affiliate KTVB, Shelton’s truck was discovered near Big Hill by Forest Service Road 256. Although his dog was found in the vehicle, Shelton was nowhere to be seen. Investigators noted “blood spatter and possible brain tissue” inside the truck.

Detectives reported, “The blood spatter appeared throughout the front of the interior,” and “The brain matter was on the rearview mirror.”

Further investigation revealed Shelton’s hair on the truck’s windowsill, and a nearby piece of mail was addressed to Bruce, as stated in the affidavit.

Phone records tracked Shelton to Bruce’s property from around midnight until 9 a.m. on May 8. Initially, during an interview, Bruce denied having any knowledge of Shelton’s disappearance. However, investigators proceeded to search Bruce’s property for further evidence.

According to the affidavit, detectives discovered possible bone fragments and broken glass behind a pickup truck. They also found “small flecks of human flesh” and red human hair — the same color as Shelton’s — next to Bruce’s camper. Police dogs indicated there were human remains in several areas of the property.

In a second interview, Bruce told investigators that he was going to prison for a “long time,” the affidavit said. Bruce said he and Shelton were involved in a traffic accident. The defendant left the area and returned with an AR rifle. Using the “cover of darkness,” he watched Shelton for “hours” from afar with night vision binoculars, detectives wrote.

At one point, Bruce said he approached Shelton armed with the rifle and asked, “Do you want some of this?” Bruce claimed Shelton was armed and responded by saying, “You better pull the trigger motherf—er” before pointing the gun at him.

“When that 45 came up it was me or him,” Bruce told detectives.

Bruce shot Shelton dead. He then proceeded to dismember Shelton’s body with a chain saw before burning the remains in a barrel. Bruce loaded the barrel into his truck, drove to a bridge and threw it into a river. He also disposed of the murder weapon and Shelton’s gun. Once he returned home, he cleaned up the scene with bleach and a Shop-Vac before towing Shelton’s truck to the Big Hill area.

When asked why he didn’t call cops, “Bruce said you ‘shoot, shovel and shut up,’” the affidavit said. Bruce also showed deputies a picture of Shelton’s body, which sat inside the victim’s truck. It was taken shortly before 6:30 a.m. on May 8.

The affidavit did not explain why Shelton was on Bruce’s property, nor did it detail his exact relationship with Bruce, though the defendant said the two were friends.

Local ABC, CBS and Fox affiliate KIFI attended Bruce’s sentencing hearing on Monday, where two of Shelton’s daughters made victim impact statements. One of the daughters reportedly said she received a disturbing letter from Bruce that said he did them a favor by dismembering and disposing of the body because they could save on funeral costs. Authorities have never recovered Shelton’s body.

Bruce was reportedly defiant during the hearing, first trying unsuccessfully to withdraw his plea and then claiming he shot his buddy Shelton in self-defense.