Steele was charged Saturday as an adult.
According to friends, neighbors and county sources, Day took Steele in as an infant, after his mother died of a deliberate drug overdose -- in front of the child.
"When they found him, he apparently was crawling around on her body," said county spokesman Mike Weland.
Sheriff George Voyles said Steele's motive is still unknown. Day was described by all as a beloved, happy member of the community. Steele, said a member of his Boy Scout troop, showed no signs of trouble. He had no criminal history, and was a freshman football player at the high school.
Deputies got a call at 2:57 p.m that a 14-year-old boy had been attacked by a bear, Voyles said.
The call came from a house adjacent to Day's off a dusty county road known as 22-B1. When deputies arrived, they found Steele, bleeding from a cut on his arm, claiming he'd been attacked by a bear.
The boy became combative with authorities, Voyles said. They restrained him and took him to the hospital.
Meanwhile, the deputies figured out where Steele lived. They found a car smashed into a tree out front, which the boy hadn't mentioned. And they found Day's husband, Duane, working in a shop behind the house. Duane hadn't heard anything, presumably because equipment could have been running, the shop is behind the house, the crash was in front of the house, and the killing was in the basement, Weland said. Duane told the deputies he was worried about his wife.
They searched the house. In the basement, the deputies found Donna Mae, injured but alive. They sped her to the hospital but not in time. Donna was pronounced dead there, from injuries caused by a blunt trauma to the head. She had also been raped with an object. Authorities wouldn't identify it or the weapon used to kill her or say if the same object was used in both crimes.
Voyles said Steele apparently wrecked the car outside, in an attempt either to leave or hurt himself.
Today, Steele will be arraigned, and Day will will undergo an autopsy.
The slaying is Boundary County's fourth homicide in 10 months, Voyles said.
"A crime like this has never happened here, that I know of," Voyles said. "It's a shock to our community. It's hard to think things like that happen."
The sheriff said he knew Day personally for 11 years. She used to work at the county, in planning and zoning. He and other friends were grief-stricken on Sunday.
"She was a true family person, an excellent, excellent cook, an avid gardener, always a friend, always willing to listen, a good mother, a fabulous wife -- the best of the best," said longtime friend and neighbor Marva Mendenhall. "She didn't deserve this. She was taking care of her daughter's child, giving him love, nurturing him."
Linda Alt has known Day since high school.
"She was just the nicest person," Alt said. "It's just awful what happened."
At the Panhandle Restaurant in Bonners Ferry, residents gathered around tables, asking questions, sharing information, remembering both Day and Steele.
"She was a wonderful lady," said Daisy Huggins. "I don't know anybody that didn't like Donna. Something horrible had to happen in (Steele's) mind."
Frank McGinnis, a freshman at Bonners Ferry High School, said that he used to be in the Boy Scouts with Steele, and that Day was involved with the group, too.
McGinnis said Steele has seemed happy, even boisterous, at school.
"He seemed like he was doing fine," McGinnis said. "Always joking around."
Voyles said he didn't know if Steele had a diagnosed mental illness. No one seems to know where his father is. Day's other daughter lives in Bonners Ferry.
"I don't think anyone will ever know why," said Anitra Skeen, daughter of County Commissioner Murreleen Skeen -- Day's best friend. "Josh had problems before, growing up, needing counseling.
"This shouldn't have ever happened. Her laugh, her smile, if anything was going wrong, Donna would make it right."
In the restaurant, townsfolk wondered why, too.
"The world's a mess," said Huggins, throwing up her hands in the restaurant. "My heart goes out to that whole family.
"It's a sad day for this town." Winston Ross can be reached at (208) 765-7132, or by e-mail at firstname.lastname@example.org.