In a killing described as "an American horror story," a man and his girlfriend were charged with murder for beating her 3-year-old son to death in their West Caln mobile home, Chester County District Attorney Thomas Hogan said Thursday.

Hogan said his office would seek the death penalty against Gary Fellenbaum, 23, and Jillian Tait, 31, for torturing Tait's son Scott McMillan to death over three days with a homemade whip, a curtain rod, a piece of aluminum siding, and their fists, at one point while he was taped to a chair.

The boy was discovered Tuesday after he died, and Fellenbaum's wife, Amber, who lives with the couple, called 911. He was covered with bruises, cuts, and puncture wounds, and his brain was bleeding.

"Our ER nurses see a lot of terrible things, but when they saw his body, they wept," Hogan said.

The couple also are charged with abusing Tait's 6-year-old son. He is being treated for his injuries at Alfred I. duPont Hospital for Children in Delaware.

The trailer on Hope Lane is also home to Amber Fellenbaum and her 11-month-old daughter with Fellenbaum. Hogan said that the Fellenbaums were divorcing and that the three adults had a friendly relationship. All three work at a Walmart stores in Parkesburg.

Amber Fellenbaum was present during the abuse, Hogan said, but did nothing to stop it. She was charged with child endangerment. The baby was not hurt and is under the care of county services, he said.

The father of Tait's sons lives elsewhere and has no involvement with his children, Hogan said.

The couple were not on law enforcement's radar, Hogan said, and police do not believe the children were being monitored by any social services agencies.

Fellenbaum and Tait are from Lancaster County, police said. They met recently at the Walmart where they work, and about three weeks ago, they moved into the trailer Fellenbaum rented, along with Fellenbaum's wife and their child.

The 270-pound Gary Fellenbaum began abusing Tait's sons almost immediately, Hogan said, starting with spankings that escalated quickly. About a week before the death, the couple hung both boys upside down by their feet and laughed as they beat them, according to a statement Tait gave police.

Tait's older son attends a Coatesville School District elementary school but had been absent for about two weeks as the abuse intensified. Police are still interviewing school administrators, Hogan said.

Neighbors of the couple never saw the children, Hogan said.

"They were living their lives in that trailer," he said.

Police do not believe drugs or alcohol fueled the violence. Instead, according to a criminal complaint, Gary Fellenbaum told police he felt "disrespected" by Scott McMillan.

On Sunday, Tait told police, Gary Fellenbaum and Tait began an extended assault of the 3-year-old, punching him and hitting him with metal objects. The next day, Fellenbaum became enraged when the child refused to eat the toast they gave him for breakfast, and punched him in the stomach and face before throwing him against a wall repeatedly. When the boy stopped responding, they put him in the shower to revive him before putting him to bed.

By Tuesday, the child's face was swollen, and he again refused to eat. The couple taped his arms and legs to a chair and beat him until he stopped moving. They also encouraged the 6-year-old brother to punch him, according to the statement Fellenbaum gave police, "for discipline purposes."

They then laid him on his bed, a deflated air mattress, and went car shopping. They stopped for pizza, took a nap, and later found that he was not breathing. Blood poured from his nose and ears.

"The brief nightmare that was his life is over," Hogan said.

Fellenbaum and Tait were held without bail Thursday. Their attorneys could not be reached. 610-313-8113 @AESteele