Joseph Edward Duncan, Serial Killer Who Slaughtered Family, Dies on Death Row

Serial killer and child molester Joseph Edward Duncan has died of brain cancer while on death row for the brutal murder of an Idaho family.

Duncan, 58, died in a Terre Haute hospital, in Indiana, near the penitentiary where he was incarcerated and waiting to be executed.

He died shortly after 2.30 a.m. PT on Sunday. Duncan's attorney said earlier this year that the serial killer had undergone brain surgery in October 2020, and was diagnosed with stage 4 glioblastoma.

Court records filed on January 21 said Duncan had declined chemotherapy and radiation and a doctor said on November 20, 2020, that the killer was expected to live between six months and a year.

Duncan was apprehended in 2005 following the brutal murders of the Grone family in May that year.

The serial killer broke into the family's home in Coeur d'Alene, Idaho, where he kidnapped Shasta, eight, and nine-year-old Dylan before killing mother Brenda, 40, her boyfriend, Mark McKenzie and Brenda's other son, 13-year-old Slade.

Duncan held the young children captive in Montana for weeks before he left Shasta at a Denny's restaurant in Coeur d'Alene. It was later learned Dylan had been molested then killed at the Montana cabin.

Duncan had also taped his horrific crimes against the two children.

Following his arrest, DNA evidence connected him to the April 1997 murder of 10-year-old Anthony Martinez in California. The young boy had been killed while Duncan was on parole for a rape charge in Washington.

While Anthony's body was found 15 days later, it wasn't until after the Idaho murders that Duncan was linked to the crime.

Duncan was also connected to the deaths of Sammiejo White, 11, and her half-sister Carmen Cubias, nine, who disappeared on July 6, 1996, after leaving a motel in Seattle.

Their remains were found on February 10, 1998, in Bothell, Washington.

Anthony's mother, Diana, told KXLY after learning Duncan had died: "The sun is a little brighter today. The world is a more beautiful place without the evil that is Joseph Duncan.

"God chose to make his end a long-suffering and I believe that is fitting. The horror of his thoughts consumed him."

Speaking to KXLY, Anthony's father Ernesto added: "While I would've liked to witness his execution, knowing he is now standing before God being held accountable for what he has done, what he did to my son and the horrible crimes he committed to others, that is the real justice."

Duncan was sentenced to death in 2007 for the Idaho murders and in March 2011, he pleaded guilty to Anthony's death and received two life sentences.

He lost his last appeal to his death sentence in 2019.