An elderly woman made an unexpected confession from a nursing home:  53 years ago, she killed her 8-month old son, Fox News reported.

The woman's other two children are now considering if she killed their twin sisters as well.

Janice Summerfield, 77, of Michigan, admitted to killing William Earl Summerfield to her 54-year-old daughter, Paula Gastian, a reporter and detective.

"I killed that baby," Summerfield said. "My mind wasn't right. I killed that baby. I didn't know what I was doing."

The boy's remains were exhumed from a cemetery grave, identified by only a number, on Oct. 16. Detective Steve Hinkley of the Calhoun County Sheriff Department has begun a homicide investigation, and the department is waiting for the results of an autopsy.

On May 29, 1961, the boy died of accidental oxygen deprivation to his brain, according to the death certificate. His older brother, Phil Summerfield, was just four when he found his little brother dead in the bed next to him.

"After she allegedly smothered the baby, she put the baby in bed with me," the man, now 58, said. "I was shy of 5 years old. I woke and he was dead. I picked him up and took him downstairs. She told me it was my fault."

Gastian and her two brothers had always been suspicious of their infant brother's death, and later, the passing of their twin sisters.  They were 3 and 11 months old when they died, respectively, the Battle Creek Enquirer reported. The children were raised in an abusive home, and Gastian said her mother often used drugs and neglected her children.

Gastian was also blamed for the death of another sister, Brenda Summerfield, in 1970.

"She was good at blaming other people. She blamed me that morning and I was 10 years old. I blamed myself for years," she said.