DETROIT, MI -- Mitchelle Blair presented herself as a loving mother of four to the outside world, but behind the walls of her Detroit apartment brutally tortured and killed, her two surviving children told agents for the Wayne County Juvenile Court during interviews this week.

During conversations with Kids Talk, a child advocacy organization that contracts with Wayne County to interview minors in cases of abuse, Blair's 17-year-old daughter said her half-brother, Stephen Berry Jr., who would have been 9, died Aug. 30, 2012.

"Their mother, Mitchelle Blair, tortured Stephen for approximately two weeks prior to his death by tying a belt around his neck, throwing hot water on him while in the shower and putting a plastic bag over his head," the court petition says in a summary of the 17-year-old's interview.

And her sister, Stoni Blair, who would have been 13, died May 25, 2013, after Blair strangled the girl with a T-shirt and suffocated her with a plastic bag.

Blair forced the eldest daughter to put Stoni's body in a "deep freezer" next to Stephen, who'd been wrapped in a blanket and placed there nearly nine months earlier, according to the petition to terminate custody.

The arrest

Blair is jailed facing four counts of first-degree child abuse and a charge of committing first-degree child abuse in the presence of another child, each crime carrying a punishment of up to life in prison.

Wayne County Assistant Prosecutor Carin Goldfarb says first-degree murder charges are possible. Blair's bond amount was set at $1 million, cash or surety.

It took three days for the bodies of Stoni and Stephen to thaw, and autopsies were performed Friday.

Both were ruled homicides, Stoni dying of multiple blunt force trauma injuries and Stephen dying of "multiple blunt trauma and thermal injuries," according to Wayne County Medical Examiner's Office spokesman Ryan Bridges.

The Medical Examiner listed March 24, 2015 at 12:49 p.m., the date and time the bodies were received by the coroner, as the official times of death.

The children were found wrapped in plastic bags in a freezer when a Wayne County Sheriff's Department bailiff visited Blair's former home in the Martin Luther King Apartments, located just east of downtown Detroit, to enforce a court-ordered eviction about 11 a.m. Tuesday.

Police arrested Blair hours later while she was babysitting children in another apartment, the Detroit News reported.

Absent fathers

The Juvenile Court petition also seeks to end the parental rights of two fathers, listing 31-year-old Steven Berry of Redford as the father of Stephen and Blair's surviving 8-year-old son; and 35-year-old Alexander J. Dorsey of Detroit, the father of Stoni and Blair's surviving 17-year-old daughter.

Dorsey, who owed $39,000 in child support according to court documents, told MLive Detroit by phone Friday he hadn't seen Stoni in about two years, but she was "fine" the last time he did.

Blair forbid him from seeing her and told him Stoni was with her aunt or a neighbor whenever questioned, the father said.

Dorsey's eldest daughter offered similar explanations, most recently when he saw her about eight months ago.

"She said what her momma told her to," Dorsey said. He lived with Blair for several years until the couple separated after the birth of their first daughter.

"I thought she'd do it to herself," Dorsey said, "I didn't think she'd do it to my baby."

Dorsey learned his youngest daughter was dead and found in Blair's freezer when a reporter contacted him Tuesday.

A man who answered at the phone number listed in court records for the Berry, father of the two younger children, abruptly hung up and didn't answer during a second attempt.

Berry, who owed more than $11,000 in child support, has two felony firearm convictions and served at least two years in prison after his latest in 2010, according to the petition.

Leaving school

Child Protective Services, once in September 2002 and again in February 2005, substantiated claims of child neglect or abuse committed by Blair, however, she retained custody of her children.

The 17-year-old daughter told an interviewer her mother pulled the children out of school two years ago.

The petition says the teen last attended a Detroit public school when she was in eighth grade, but Detroit Public Schools spokeswoman Michelle A. Zdrorowski, citing privacy rights, wouldn't confirm if any of the children ever attended Detroit Public Schools.

Parents in Michigan have no obligation to notify their school district or the state Department of Education if they plan to home-school, although it is recommended to avoid suspicion of truancy, the state website says.

There is no statewide mechanism that alerts administrators or child care professionals to check on students who are removed from a school system.

Blair never submitted optional documentation to notify the state Department of Education she was home-schooling the children, according to a search of the system by Michigan Department of Education Analyst Tami Feldpausch.

She said parents who home-school their children must only register with the state if they are seeking special education assistance.

The scars

Neighbor Jessica Porter, 28, said Wednesday she knows the two surviving children, but only met Stoni through a window, and never saw the youngest.

Porter said Blair "loved those kids," home-schooled them and "super-glued" their assignments to the walls in the living room.

On the day the bodies of their siblings were discovered, the surviving children received medical examinations and they "disclosed being abused throughout their childhood by their mother," the petition says.

Medical professionals identified "25 scars and injuries, both old and new," on the 8-year-old's back, as well as "loop-shaped scars and injuries" on his back and buttocks that are consistent with being whipped by an extension cord, according to the custody petition.

When asked about the "visible cut" above her left eye, the 17-year-old told the interviewer Blair struck her in the head with a 2-by-4; the broken front tooth was from the time the teen's mother hit her with a curling iron.

The teen, who also had scars from being burned with irons and whipped with cords, said Blair refused the children medical treatment.

She continued receiving $771 per month in food assistance and Medicaid benefits for all four children through the date of her arrest, and received child support payments from Berry for Stephen as recently as December.

Blair is scheduled to return to court April 2 for a probable cause hearing in her criminal case and again on April 9 for a preliminary examination to determine if the case will be bound over to the Wayne County Circuit Court for trial.

Blair's custody of her living children has been suspended pending Juvenile Court proceedings. She is scheduled to return to the Wayne County Juvenile Court for a pretrial in the matter April 8.

The fathers are currently allowed supervised visitation, as Child Protective Services seeks termination of parental rights.

Child Protective Services is seeking a court order that would allow the agency to put the surviving children up for adoption.

Dorsey told MLive Detroit he's been avoiding media reports since first learning about his daughter's death Tuesday.

"I don't know what to say about it," he said. "It's just unbelievable.

"Unbelievable."