A woman attacked with a machete in her western Minnesota home last month died on Mother's Day, and her son has been charged in an attack that he described as a mercy killing, authorities said.

Barbara K. Howard, 68, of Dalton, died Sunday morning at Sanford Medical Center in Fargo, the Otter Tail County Sheriff's Office said Monday.

James F. Howard, 46, was charged on April 26 with first-degree attempted murder and assault in the attack three days earlier. Charges say that he admitted to trying to kill himself.

With his mother's death, the county is expected to upgrade the charges to murder.

James Howard told paramedics called to the home near Stalker Lake, about 20 miles southeast of Fergus Falls, that he was trying to end his mother's pain from cancer and diabetes, according to the criminal complaint.

"[I wanted to] do it quick, with no suffering," the complaint quoted him as saying.

Barbara Howard suffered a skull fracture on the left side of her head, the complaint said, and several of her fingers were nearly severed as she tried to block the machete swipes.

James Howard told paramedics that he tried to hang himself, but that failed, so he then cut his throat. After receiving medical treatment, he was taken to the county jail and remains there.